Few studies have been conducted to examine the role shyness plays in friendship selection and influences processes, particularly how befriending shy peers affects individual's psychological adjustment. To address these gaps, this study investigated the selection, de-selection, same behavior influence effects of shyness in the friendship network in Chinese adolescents using the longitudinal social network analysis. It also explored the possible pathways that transmit indirect influences of friends' shyness to individual's psychological maladjustments (i.e., loneliness and depressive symptoms). A sample of adolescents (N = 1254, 48.4% girls, Mage = 13.20 years at Time 1) were followed for three years in middle schools. The results showed that adolescents tended to befriend those who had similar shyness level during T1-T2 interval, but the friendships between shy friends were more likely to terminate during T2-T3 interval. Moreover, adolescents were found to become more similar with their friends in shyness over time. The study also found that friends' shyness at T1 would influence individual's loneliness at T3 via 1) increasing friends' loneliness at T2 or 2) increasing individual's shyness level at T2. Those two pathways, however, were not found for depressive symptoms. These findings indicate that shyness plays an important role in the friendship formation and dissolution and befriending shy peers may have implications for adolescents' development of shyness and loneliness.