Abstract: Haemogregarina sinensis in its life cycle requires two hosts: the vertebrate host Trionyx sinensis and the invertebrate host Mooreotorix cotylifer. This paper describes the developmental stages of this parasite in a Chinese turtle, Trionyx sinensis, which consists of schizogony in the Kupffer's cells in the liver, schizogony in the deep blood cells and schizogony in the peripheral red cells. Schizonts with 14—32 merozoites were found in the Kupffer's cells. Xschizonts containing 14—18 merozoites and Y-schizonts containing 4—6 merozoites were recorded from liver imprints. The male-and female-gametocytes in peripheral red cells probably come from Y-merozoites. In peripheral erythrocytes, the initial schizonts produced 14 merozoites; whereas in the last stage of schizogony they produced only 2 merozoites. Movement of trophozoites was observed in peripheral blood.