Responsibility has been one of the most important and significant structures in the recent years and identifying the factors that influence it is important. This research was conducted with the aim of examine the role of identity dimensions as mediating relationship between family communication patterns and responsibility in emerging adulthood. The research method is a correlation of type structural equation modeling analysis. The population of this study included undergraduate students at the age range of 18-29 years old in Shiraz University in year 2017-2018. 537 students (322 female and 215 male) were selected using multi-stage cluster random sampling method and to responded Responsibility, Dimensions of Identity and Family Communication Pattern Questionnaires. Data were analyzed using structural equation modeling analysis and AMOS statistical software and fitness indices. The findings showed that the proposed model has a good fit and the path coefficients are significant communication pattern to personal and social responsibility, conformity communication pattern to personal responsibility, conversation communication pattern to commitment component of identity and conformity communication pattern to exploration component of identity. Also, commitment component of identity has mediating role in the relationship between family communication pattern and responsibility. In sum, can be concluded that is important role of conversation communication pattern in emerging adulthood’ s identity formation and responsibility.