Abstract Yi people deeply affected by Jiazhi group. Compared with Han people who have two tier group structure what are Chinese identity and Han ethnic identity. Yi people have three-tier group structure what are Chinese identity, Yi ethnic identity and Jiazhi identity. Previous studies found that the Yi people have a high identity of Chinese national identity and the ethnic identity. So, whether the Yi people’s unique Jiazhi identity also have a high level and have a positive impact on well-being. However, at present, the research on Jiazhi of Yi people mainly through interview method, field investigation method and the literature method and lacks quantitative research. So we introduce social identity theory of psychology to studying Jiazhi structure and we also revising the Jiazhi identity scale of Yi people according to the internal group identity scale in order to further explore the relationship between national identity and Jiazhi identity and find out how is it impact on Yi people’s well-being. In study one, according to Colin Wayne Leach ingroup identity scale, we revised the Jiazhi identity scale, and using it to measure Yi people’s Jiazhi identity level. We found that the questionnaire has a good degree of reliability and validity. In study two, we found that, firstly, the Yi people's Jiazhi have an important impact in daily life, Yi people have a higher Jiazhi identity（M=4.79，SD=1.16）. Secondly, we found that Yi people have a higher ethnic identity（M=4.00，SD=0.51）and Chinese nationality identity（M=3.98，SD=0.53）which is similar to the previous results. Thirdly, we found that Yi people are agree with their own ethnic culture（M=4.30，SD=0.616）and have a strong sense of belonging（M=4.47，SD=0.47）in their daily life. Then we also found that the well-being of the Yi people is in the middle upper level（M=3.29，SD=0.55）which is similar to the previous results. More specifically, the most satisfactory in terms of well-being is health satisfaction（M=3.80，SD=0.87）and relatively the lowest satisfactory is economy satisfaction Finally, we found that the ethnic identity of the Yi people has a regulatory role on well-being and Jiazhi identity. Yi people’s Jiazhi identity support for the sense of well-being and have a significant positive prediction on it. More specifically, a higher ethnic identity, means the Jiazhi identity has a stronger prediction of Yi people’s well-being. For national identity, In China, national identity includes the Chinese national identity and ethnic identity, in which the Chinese nation is the upper group, and the nation is the lower group, constitute a two-tier group structure. In the identity of the Yi people, in addition to both the identity of the ethnic, but also deeply affected by the impact of Jiazhi support. Compared with the Han people who have two tier group structure what are Chinese identity and Han ethnic identity. the Yi people have three-tier group structure what are Chinese identity, Yi ethnic identity and Jiazhi identity. Previous studies have found that the Yi people have a high identity of the Chinese national and the ethnic identity. So, whether the Yi people’s unique Jiazhi identity also has a high level and have a positive impact on well-being. However, at present, the research on Jiazhi of Yi people mainly through the interview method and the field investigation method and the literature and lacks the quantitative research. So we introduce the social identity theory of psychology to studying Jiazhi structure and we also revises the Jiazhi identity of the Yi people according to the internal group identity scale. In order to further explore the relationship between national identity and Jiazhi identity and find out how is it impact on Yi people’s well-being. In study one, according to Colin ingroup identity scale, we revised the Jiazhi identity scale, and using it to measure Yi people’s Jiazhi identity level. We found that the questionnaire has a good degree of reliability and validity. In study two, we found that, firstly, the Yi people's Jiazhi has an important impact in daily life, Yi people has a higher Jiazhi identity(M=4.79，SD=1.16). Secondly, we found that Yi people has a higher ethnic identity(M=4.00，SD=0.51) and Chinese nationality identity(M=3.98，SD=0.53) which is similar to the previous results. Thirdly, we found that Yi people are agree with their own ethnic culture(M=4.30，SD=0.616) and have a strong sense of belonging(M=4.47，SD=0.47) in their daily life. Then we also found that the well-being of the Yi people is in the middle upper level(M=3.29，SD=0.55) which is similar to the previous results. More specifically, the most satisfactory in terms of well-being is health satisfaction(M=3.80，SD=0.87) and relatively the lowest satisfactory is economy satisfaction. Finally, we found that the ethnic identity of the Yi people has a regulatory role on well-being and Jiazhi identity. Yi people’s Jiazhi identity support for the sense of well-being and have a significant positive prediction on it. More specifically, a higher ethnic identity, means the Jiazhi identity has a stronger prediction of Yi people’s well-being.