Although this people group calls itself merely Nasu, an added description is needed in order to separate them from other groups who refer to themselves as Nasu but who speak different languages and dialects. The Southern Nasu are also different from the Nisu in Xinping and Yuanyang counties who have been profiled separately.

The Southern Nasu probably originated in southern Sichuan and northern Yunnan many centuries ago. The name Nasu means "black people." The color black is revered by the Nasu.

The Southern Nasu retain many aspects of their traditional culture, including the four-stringed guitar and a host of folk dances and songs. They also participate in the annual Torch Festival which takes place on the 24th day of the sixth lunar month.

The Southern Nasu are polytheists who attempt to placate a wide array of spirits and deities. Some spirits are considered helpful while others are evil and cause death, sickness, and destruction. One source says, "Animistic spirituality and ancestor worship is alive and well among this people. The Southern Nasu of Eshan County still have living bimos or sorcerers who perform rites and incantations from the ancient script to appease demons and ward off evil from sick persons, households, and at funerals. Besides the bimo there is a significant number of ordinary people who have linked themselves with the spirit world, and are able, through such channels, to heal sicknesses."

There are presently only about 100 known Christians among the Southern Nasu. These believers meet in Han Chinese churches in the townships of Yuxi Prefecture. There is no Nasu-language congregation in existence. Today most Southern Nasu have no knowledge of Christianity. Mission work among them prior to 1949 was nonexistent. In 1998 the Christian ministry Gospel Recordings produced audio tapes of the gospel message in Southern Nasu, resulting in a few people making decisions to follow Christ.

Scripture Prayers for the Nasu, Southern in China.