Although scholars have been making progresses in drawing the outline of Sabao (s’rtp’w), the official position brought by
the Sogdian immigrants into the
bureaucracy system of the Northern Dynasty and Sui Tang China, by using new materials discovered from Sogdians’ graves and epitaphs, it remains difficult to describe it in detail. After carefully comparing the official titles of Sabao recorded in epitaphs with the official rank systems written in historical literature and other ethnic leaders’experiences of serving in local government, the present study, however, deepens our understanding of Sabao, by suggesting that its rank and status in bureaucracy system was approximate to that of the District Magistrate. Approaching the course of disintegration of the Sogdian
settlements from the end of the Northern dynasty to the beginning of the Tang dynasty from three aspects: the changes of Sabao’s official rank, the deviation from the inheriting tradition and the way of appointment, this study also points out that the bureaucracy system which the central government used to enhance the Sogdian chieftains’ social mobility played the significant role in this historical course.