This study tests social control, strain, and differential association theory of delinquency by considering the effects of family, school and peer factors and their psychological intervening variables. Using data from surveying 715 male and female middle school students, our findings support strain theory by showing that strain in relationship with parents has an effect on negative emotion, which in turn has a significant effect on delinquency. In addition, the effect of association with delinquent peers on delinquency is direct and also mediated by delinquent attitude, which supports differential association theory. Results support social control theory. That is, attachment to parents has an indirect effect on delinquency through the perception of anticipated negative reaction by parents. Result reveals that the effect of delinquent peers is the largest but negative emotion is the most important psychological intervening variable. Our findings show mixed results.