Abstract: The author observed the zygomatie bone of 400 sides of 200 adult skulls collected in the region of Ying Chuan, Ningxia. The results obtained are summarized as follows:
1. Ineidence of incomplete zygomaticum bipartium of unilateral side is a little higher than that of bilateral sides; both of them are 21. 5±2. 90%.
2. There are differences of the incidence of the sutures of the incomplete zygomaticum bipartium. The orders of them can be arranged as the following: the posterior horizontal suture is the most, the anterior horizontal suture, the second and the complete one, the last.
3. Incidence of the complete zygoticum bipartium is limited, and that of the bilateral sides is a little higher than the unilateral side, but the difference between the left and the right of the unilateral side is not remarkable (u=0. 82).
4. Zygomatieum tripartium is rarely seen, only two cases of the right side (1. 0±0. 5%) .

Key words: Zygomatic bone