This study investigated the problem-solving process using distraction in interpersonal stress situations among undergraduates. Undergraduate participants ( N =223) were instructed to recall a recent personal experience of being depressed by an interpersonal stressor, and then completed a questionnaire which measured concentration on distraction, positive mood, problem-solving behavior, distraction frequency, rumination, and knowledge of effective activity. The results of path analysis suggested that concentration enhanced problem-solving through increasing positive mood as previous study. Knowledge of effective activity was an important key to enhance the effect of distraction on problem-solving through enhancing the frequency of distraction and reducing rumination.