The Primis is the descendant of ancient Qiang ethic group, which used to be the strongest Ethnic Minority in the northwestern China (now in Gansu and Qinghai Province). Their force had once covered the whole Qinghai Province and the northern Tibet. However, during the middle of 7 century BC, the tyrant of Qin took the suggestion of his consultant, Youyu, who said that the king of Qin should unify the twelve countries in the north including the Qiang tribe.

The west Qiang failed in the battle with Qin. So one part of the Qiang tribe migrated to the Qinghai-Tibet altiplano, across Jinsha River, arriving in the up reach of the Yalong River. During the Han and Tang Dynasty, they settled in an area in the west of the Mount. Qionglai in Sichuan Province, which is in the middle of Jinsha River, Yalong River and Dadu River. It is during Yuan Dynasty when the Primi Ethnic Group formed, which is an important period for the development and migration of the Primis. At the beginning of the Yuan Dynasty, a large group of the Primis (called Xifan at the time) followed the Mongolia troops entering the northwestern Yunnan Province.

The rest who had not migrated into Yunnan Province stayed there and mixed with those Xifan ethnic groups, who were till the main settlers from the south of Dadu River to Jinsha River. From then on the distribution of the Primi was becoming more stable. After the Ming and Qing Dynasty, the Primis in the western Sichuan Province integrated with Tibetan because of the influence of Tibetan Buddhism. However, the Primis in the northwester Yunnan Province still mostly well kept their traditional custom and gradually developed into a mono ethnic group which is different from the Primis in Sichuan Province.