The purpose of this study was to design a conceptual model for identity formation among college students. Therefore, five objectives were taken into account: identifying the dimensions and characteristics of identity formation, determining the effective factors for identity formation, comparing students’ identity status between the first and last terms in ideological dimension, comparing students’ identity status between the first and last terms in interpersonal relationship dimension and developing a model for the role of universities in improving students' identity. A mixed applied research method was chosen for this study. Utilizing archival method, 4 dimensions and 36 components of students' identity formation were identified. Using a survey method and stratified-cluster sampling, a 65-item questionnaire was administered among 613 first/Last-semester students. Data were analyzed by binominal test, independent t-test, multivariate analysis of variance and chi square test. The findings showed that the identity status of last-semester students was lower than first-semester students. A model for improving students’ identity formation was designed. The degree of fit of the final model was approved by 24 faculty members, administrators and academic experts.