Hemocytes were collected from Oncomelania hupensis in Junshan, Hunan Province and Puge, Sichuan Province, respectively, and stained with Giemsa solution for light microscopic examination. The cells were classified morphologically. Five types of hemocytes were identified, viz., large acidophilic hyalinocytes, small acidophilic hyalinocytes, basophilic hyalinocytes, basophilic small granulocytes and basophilic large granulocytes. The proportion of small acidophilic hyalinocytes was the most abundant hemocyte [36.7% (229/624) in snails from Junshan and 31.7% (257/810) in snails from Puge], followed by basophilic hyalinocyte [23.1% (144/624) in Junshan and 24.4% (198/810) in Puge]. Basophilic large granulocyte was about 9.3% (58/624) in Junshan and 11.6% (94/810) in Puge. The length of large acidophilic hyalinocytes was the maximum and its nucleocytoplasmic ratio was minimum, followed by small acidophilic hyalinocytes. The length of basophilic cells was shorter and its nucleocytoplasmic ratio was smaller than those of acidophilic cells. There was no significant difference in cellular constituents of hemocytes and the morphological features of hyalinocytes between the snails from Junshan and Puge, while the length and nucleocytoplasmic ratio of granulocytes in Junshan snails were smaller than those of Puge ones.