Correlation analysis showed that, among left-behind children, social anxiety is moderately related to loneliness, which is consistent with Peplau, Miceli, & Morasch [10] and Murray, Robert, & Adam’s [14] studies of this relationship. Mette, Maurice, & John pointed out that interpersonal stress was significantly correlated with mental pain, somatic symptoms, while social networking can moderate the relationship between interpersonal stress and psychological distress [32] . Individuals with high levels of social anxiety tend to expect negative evaluation by others in interpersonal situations, and are therefore likely to interpret neutral evaluation as negative evaluation, and consequently to worry about this [33] . In life, an individual’s loneliness is likely to affect their social behavior. It is often difficult for individuals with high levels of loneliness to establish and maintain good interpersonal relationship, and they feel painful to unsatisfied such relationships [10] . Adolescents with high loneliness often have more anxiety, anger, negative emotions, and fear of negative evaluation, are less optimistic, have poorer social skills, and lower social support, positive mood, emotional stability, extraversion, agreeableness,

conscientiousness, shyness and social skills [34] . Left-behind children in rural areas are a vulnerable group, and if they are lonely for a long time, there is a risk they will become socially maladjusted and have a poor sense of belonging to their community.

In this study, positive coping style was negatively correlated with social anxiety and loneliness among left- behind children, while negative coping style was positively correlated with these variables. Ray and Lindop believe that coping style is a kind of behavior used to solve or eliminate problems, and its purpose is to change the environment or the negative emotional experience from environment through the individual’s efforts [35] . Everyone has different psychological coping mechanisms and will take certain coping style to ease the pressure from the impact on their mood. Positive coping styles, like problem solving, help seeking, and rationalization, will play an important role to ease the social anxiety and loneliness, while negative coping styles, like fantasy, retreat and remorse, will easily make individual trapped in anxiety and loneliness. Left-behind children who utilize positive coping styles will experience less anxiety and loneliness, whereas the opposite will result from taking negative coping style.

The study showed that social anxiety among left-behind children increased significantly with grade increasing, which is consistent with the studies of Wang, & Chen [16] , and Chen, Ma, & Dai [23] . Low grade children tend to overestimate themselves, and their evaluation is often the subjective self-assessment. While with the increase of age, children’s self-consciousness will strengthen gradually, and they will pay more attention to their words and deeds and how others may evaluate themselves. This internal focus may cause anxiety. Parents are migrant workers which impact their spiritual growth, especially social intercourse and interpersonal relationship. And the degree of negative impact of both parents outing is higher than one parent outing. Therefore, parents’ parenting has positive effect on children’s social interaction process. However, the social anxiety and loneliness scores of non-single children were significantly higher than single children, which are contract to experience and has no relevant evidence about this aspect.

There were significant differences in coping style among grades: the scores of high grade students were significantly higher than those of low grade students. The result showed that, as age and education increased, left- behind children would be more able to solve the problem. Left-behind children with both parents outing take less positive coping style than one parent outing and negative coping style is just the opposite, which states that if lack of family education, especially parents education, it is unfavorable for children to choose appropriate coping styles.

In the study of Jinkwan, Ronald, Rapee, & Hye-Shin, social withdrawal of adolescent resulted in early adulthood will cause social maladjustment, and decreasing loneliness must need better social and emotional adjustment ability [36] . However, coping style is closely related to social adjustment and the coping style or confronting style for seeking social support is important predictors of positive social adjustment, and loneliness, as an aspect of psychological symptoms, will easily produce through the individual’s choice of negative coping stylet [22] . Hu, Liu, & Shenfound that the positive coping style had a significant negative correlation with psychological symptoms among left-behind children [37] .

If individuals often use or active in cognitive assimilation the positive coping style such as problem solve, ask for help and rationalization etc., it will be great beneficial to moderate social anxiety, so as to dissolve the loneliness. It can be concluded that the positive coping style and the positive psychological trait can bring positive effect to left-behind children’s mental health. But, if someone take negative coping style more frequently, such as fantasy, retreat or remorse, it would be easier to make him or her in a vicious cycle of anxiety and loneliness and cannot extricate oneself. So, when the left-behind children appeared social anxiety, on different levels to take positive or negative coping styles, it will be significant mediate effect on loneliness. And this tell the teachers and parents that if anyone want to help reduce the loneliness of left-behind children, carry out rational education of coping style is necessary and feasible.

The results of constructing the equation model showed that, social anxiety (fearing of negative evaluation and social avoidance and distress) of left-behind children have direct significant predictable effects on loneliness. Children with high social anxiety often lack communication with others, and then cause loneliness and adjustment confusion, and meanwhile may bring a series of psychological problems [23] . Stephen, Kelly, Karen, & Kelly argues that in early adolescence, close friendship will effectively ease children’s social anxiety and loneliness and improve their social self-efficacy [38] . From the two points, social anxiety can predict loneliness.

Further study of the model, social anxiety of left-behind children affected loneliness through coping style. Compared with positive coping style, social anxiety had more indirect prediction effect on loneliness through negative coping style. This study confirmed that the negative coping style is one of the reasons of producing the negative emotion and interpersonal problems. If left-behind children take the negative coping style to deal with social communication problems, they will get deeper lonely experience. By contrast, if they take positive coping style, loneliness caused by social anxiety will be eased. Satisfying social relations are essential to individual’s mental health, so how to improve social relationships becomes the focus of society [39] . It is impossible for negative coping style to establish satisfying social relations. Therefore, education should first teach left-behind children stopping or reducing taking negative coping style, and then increase taking positive coping style to improve interpersonal communication, interpersonal adaptability and satisfaction.