Using social network analysis approach, the current study was investigate the predictive power of depressive friends in class on the chance of college students becoming depression. The present study hypothesizes were tested using data from 73 classes composed of 3034 individuals. The main findings were as follows : ( 1 ) The quantity of mutual friends had negative predictive power on depression. (2) There was no difference between the students who' s had at least one depressive mutual friend and the students whose mutual friends are all n...