Blended learning is a mixture of the various learning strategies and delivery methods that will optimize the learning experience of the user. This research evaluated psychological effect of blended learning on student.This research is a quasi-experimental study. 41students participated in two groups and they registered in the course of psychological diseases in the first semester of 2008–2009. Then, they were randomly divided into groups of traditional and blended methods. Data were gathered through Attribution Measurement Test and Neo Personality Test (Neo FFI).Descriptive statistics were used to evaluate the patterns of data distribution. Analytic statistics such as paired-t test and student t-test were utilized to compare the differences of between the mean scores in pre and post tests. Then analysis of variance (Manova Test) and chi square tests applied to evaluate the effects of research variables on each other. The mean score of academic achievement in the blended education group (Mean=15.67, SD=1.65, T=3.06, p=0,004), was higher than that of the traditional education (Mean=13.88, SD=2.06). In surveying the interaction between attribution style, type of teaching, and scores of academic achievement, it was revealed that there was a significant relationship between global–local favorable condition (P=/04, F=10/52). Evaluating the interaction between type of teaching , student’s final scores and personality type based on MANOVA TEST revealed that, there was a significant relationship between all personality factors(openness, extraversion, agreeableness and conscientiousness), except neuroticism criterion. The use of this educational method with standard designing strategies is recommended for teaching medical sciences.