Abstract: 【Objective】 This study aims to investigate the influence of swimming training on blood parameters of horses and analyze the changing rules of blood parameters of horses in different training phases in the hope of providing theoretical support for Yili horse swimming training. 【Method】 12 Yili horses were trained for 42 days in different lengths, blood samples were taken immediately after training every 14 days, and blood samples were measured. 【Result】 With the increase of swimming training days, the AST of horses at 14 d and 28 d was significantly lower than that at 0 d (P<0.05), CK activity was significantly lower on the 0th and 28 th day than that on the 42 nd day (P<0.05) and it was extremely significantly lower on the 14 th day than that on the 42 nd day (P<0.01). The 0th of PvO₂ was significantly lower than that of the 28 th day (P<0.05), Hct and Hb were significantly lower on the 0 th than those on the 42 nd day (P<0.05); In different durations of swimming training, the CREA and TG in the test group 1 were extremely significantly higher than those in the control group (P<0.01), and were significantly higher than those in the test group 2 (P<0.05); The UA in the test group 1 was extremely significantly lower than that in the control group(P<0.01), and was significantly lower than that in the test group 2 (P<0.05); The CK in the test group 2 was significantly lower than that in the control group (P<0.05); The Hct and Hb in the control group were extremely significantly lower than those in the test group 2 (P<0.01), and in the test group 1 (P<0.05). 【Conclusion】 In the case of consistent land training intensity, swimming training for horses can effectively increase the oxygen carrying capacity of red blood cells and lung capacity, and it also can reduce the damage of horses' limbs and hoof caused by terrestrial training, so it can be one of the subjects of daily training for Yili horses.