The Qinghai-Tibet Plateau is a vast area with high mountains and steep roads. Throughout its long history, it has gradually divided into three distinctive cultural regions, namely "Ü-Tsang, Khampa, and Amdo". There is also a saying that "Ü-Tsang is the land of Buddhism, Amdo the land of horses, and Khampa the land of people".
The Yushu region, where Angsai is located, is part of the Khampa Tibetan region. Khampa has always been in a transitional zone between the Han and Tibetan groups, and has distinct characteristics in administrative, religious, economic and cultural aspects. The Khampa people are known for their straightforward ethnicity and religious devotion. They have a tradition of business and travel and are relatively strong.
In the early days, the Qinghai-Tibet Plateau was scattered with large and small clans, and human have been living and working in the area of Yushu since at least 8,100 years ago. During the period of the Tubo Kingdom, Yushu was a part of Supi and was considered one of the brightest pearls on the Tang Fan Acient Road. Throughout its history, Yushu has had more than 70 tribes, which evolved into a total of 40 tribes by the year 1732, and the number fell into 25 by the mid 20th century. These tribes are known as "the 25 tribes of Yushu". The county of Zaduo used to belong to the "Four Tribes of Gegi", and therefore Zaduo is also known by the local people as "Gegi Zaduo".
The tribes of Gegi are divided into Gegi Doma and Gegi Mima, and Angsai Township is the birthplace of Gegi Mima tribe. The tribe underwent the Mongolian invasion, and was ruled during the ROC period by the Ma family, whose brutal oppression was met with heroic resistance. When Yushu was liberated in 1949, the tribe of Gegi Mima was one of the hundred households of Nangqen. In 1958, the Gegi Angsai tribes had 360 households with a total of 1,080 people. The stories of Gegi tribes are widely told among people. Any elder from the area will know no less than any history book.