many people hope to improve their own or their children's life abandon their own country and move to other places. One of the basic discussions in social sciences is the problem of the immigrant's intergration in the new place and the problem of how they can adopt themselves to the new environmental and cultural circumstances. Being an alien to the new cultural principles and values cause various behavioral and mental consequences for the immigrants. Nowadays, this has become a serious problem in many societies and has changed from a social phenomenon to a social problem. This study aims to explain and explore those factors which affecting mental health of migrants who were living in Islam Abad (West of Iran) under the time the research. data were collected through structured questionnaire from 600 migrants who were selected randomly. To test the hypotheses, Pearson correlation coefficient and analysis of variance were used. Multiple regression and path analysis were used to assess the research model. According tp the research findings, there is a significant relationship between the immigrants mental health and social capital (r=0 .73), coping strategies ( r=0 .65), and acculturation stress (r=0 .61). Regression results show that the five variables: social capital, social class, coping strategies, acculturation stress and maritas status have had significant effects on mental health. They have explained 75 percent of the changes in mental health (R2=0 .75). It should be mentioned that social capital has directly and most causal effect on mental health and income has indirectly and most causal effect on mental health. A high degreeof mental health among the immigrants is a result of an increase in the amount of social capital.