In Eastern Turkestan, the Moslem rebellion of 1864 resulted in the establishment of the government of Ya'qub Beg. It has been one of the main themes of the recent research on this government as to whether its main constituents were the Turko-Islamic natives in Eastern Turkestan (often called the Uighurs) or were those who came from abroad. In this article, the author investigates the government of Ya'qub Beg from a personnel point of view. After the revolt broke out in 1864, a lot of people arrived in Eastern Turkestan chiefly from the Khoqand Khanate in Western Turkestan. They were selected and organized into the main body of the conquest army under the command of Ya'qub Beg. At the same time, Ya'qub Beg seized power in Kashghar. Afterwards, most parts of Eastern Turkestan were conquered by him, and the government of Ya'qub Beg was established. On the other hand, some influential Uighur figures supported Ya'qub Beg in face of his conquests, especially in the cities of Yarkand, Aqsu and Kucha. Therefore, we need to investigate the civil officials and military officers of the government. In the first place, the civil officials can be divided into the central government and provincial government officials. The posts of mirza (secretary) in the central government were occupied by those who had come from Western Turkestan. On the other hand, both the Khoqand Khanate people and the Uighurs were appointed to the posts of hakim beg, which occupied the top posts in the provincial governments. Most of the posts of the various judicial officers in each province were occupied by the Uighur natives who lived in the same province. Next, the high ranking military officers regarded as the commanders of garrisons, which were stationed in the main cities after they were conquered, almost all consisted of those who had come from abroad, mainly from the Khoqand Khanate. It can be thought that they formed a kind of stratum of the high ranking military officers all over the territory ruled by the government. The military officers appointed to the commanders in military operations also consisted of those who had come from abroad. So it is obvious that most of the principal military officers, who played a role in the period of Ya'qub Beg's rule, were those who had come from the Khoqand Khanate. Such a disposition of the officials is not contradictory to the military regime formed and controlled by a conqueror. Accordingly, it is difficult to insist that the government of Ya'qub Beg was mainly composed of the Uighurs. But we should not neglect the fact that some influential Uighur natives actually supported that government. In any case, we will have to shed more light on the character of this government in future research.