Sinilabeo decorus tungting, which belongs to Cyprinidae, Barbinae and Sinilabeo, is a large fish and endangered species distributed only in Hunan Province of China. In order to find a suitable culture environment, we studied the characteristics, immunofunctions and impact factors of peripheral hematocytes in S. d. tungting under different cultivation conditions (cage culture, cement-pond culture and soil-pond culture) (Table 1). The peripheral blood cells from 30 individuals were examined, classified, counted and photographed under the light microscope by blood smear, the diameters of various hematocytes and their nuclei in shortest and longest axes were measured using routine methods, and the immunofunctions of neutrophils were detected through phagocytosis test and nitroblue tetrazolium reduction test (NBT). The experimental data were analyzed with SPSS23.0, and the pictures were processed with photoshopCS. The results showed that the peripheral blood cells of S. d. tungting could be divided into five types as erythrocytes, thrombocytes, granulocytes, lymphocytes and monocytes, as shown in Fig. 1. The mean size of mature erythrocytes in length × width was 7.36 ± 0.58 μm × 5.16 ± 0.33 μm, while the largest blood cell in the peripheral blood cells was monocyte with a mean size of 11.93 ± 0.86 μm × 10.16 ± 0.76 μm (Table 2). The red blood cells consist of the largest proportion (over 80%) of peripheral blood cells, whereas the content of thrombocytes in low proportion white blood cells was as high as 70%﹣74% (Table 3). Among the three cultivation methods, the red blood cells number in cage culture was significantly lower than that in cement-pond culture or soil-pond culture (0.01 < P < 0.05); the number, type and ratio of white blood cells were relatively stable and did not change significantly with cultivation methods (P > 0.05, Table 3). In the phagocytosis test and nitroblue tetrazolium reduction test, results showed that the phagocytic percentage and phagocytosis index of neutrophils in cement-pond culture were significantly lower than in cage culture and soil-pond culture (0.01 < P < 0.05), and the positive rate of nitroblue tetrazolium reduction test was the lowest (P > 0.05). Therefore, the phagocytic and bactericidal ability of neutrophils in cement-pond culture was the worst (Table 4). According to the results of our experiment, S. d. tungting is suitable to live in a flowing, good quality water environment.