Abstract: Introduction: In order to validate and investigate reliability of the Weightefficacy Life Style Questionnaire (Clarck et al , 1991 ) . Method: 100 randomly selected student of Shahid Beheshti University participated in this study. Applied methods were: item analysis (degree of difficulty, discrimination coefficient, loop method), validity (content validity, construct validity that consists of confirmative factor analysis and internal correlation )and reliability of factors and total score.in cofirmative factor analysis 5 factors (negatiye emotions, availability, social pressure, physical discomfort and positive activities) were confirmed. Result: The reliability of this test (Cronbach,s Alpha) for facors was between 0.71 to 0.78. Conclusion: considering result of this study, the Weight efficacy Life Style Questionnaire is reliable and can be use in relate to eating behaviors and weight control researches in lran.