This study examines the effectiveness of positive thinking skills training on student’s happiness. In this study, using a twogroup experimental design, 30 female students from Sharif University were chosen. These subjects randomaly assigned two groups (each with 15 Ss.). Oxford Happiness Questionnaire was administered for both groups in pretest condition. The experimental group experienced an eoght session interrention on positive thinking skills training. Research findings revealed that the applied intervention significantly increased happiness and its components. In sum, the results emphasized the cognitive manipulation effects on subjective happiness.