Abstract: In order to explore the effect of different doses of foot-and-mouth disease vaccine on the quality of bull semen, the experiment selected 21 Holstein and Simmental bulls, aged 2-9 years old, weighing 800-1 000 kg, which was divided into 2.0 mL group, 1.5 mL group, and 1.0 mL group, with 7 bulls in each group, and were injected with different doses of trivalent inactivated foot-and-mouth disease vaccine containing types O,A,and AsianⅠ. The changes of quality indexes such as fresh semen dose, sperm density, sperm vitality, sperm deformity rate, and utilization rates of fresh semen in 180 days after immunization were analyzed. The results showed that compared with before immunization, after Holstein cattle being immunizied, the fresh semen doses in 1.0 mL and 2.0 mL groups decreased from 1-60 d, and increased in 1.5 mL group, but there was no significant change in each group（P＞0.05）. Sperm density increased and sperm vitality decreased in each group, but the change was not significant（P＞0.05）. The sperm malformation rate increased, and the increase in the 1.0 mL group was not significant（P＞0.05）. The 1.5 mL and 2.0 mL groups increased significantly at 1-30 d and 1-60 d, respectively（P＜0.05）. After immunization, the utilization of fresh sperm in each group decreased first and then increased, and decreased to the lowest level at 1-30 d, and did not return to the pre-immunization level at 180 d. The decrease in 1.0 mL group was not significant（P＞0.05）. The decrease in 1.5 mL group was extremely significant at 1-60 d（P＜0.01）, and was significant at 61-90 d（P＜0.05）. The decrease in 2.0 mL group was extremely significant at 1-60 d（P＜0.01）, and was significant at 61-120 d（P＜0.05）.Compared with before immunization, the fresh semen doses of Simmental bulls in each group decreased but had no significant change（P＞0.05）. Sperm density first increased and then decreased, The 1.0 mL group decreased extremely significantly at 121-150 d（P＜0.01）and significantly at 151-180 d（P＜0.05）, 1.5 mL group increased significantly at 1-90 d（P＜0.05）and decreased significantly at 121-150 d（P＜0.05）, 2.0 mL group decreased extremely significantly at 121-180 d（P＜0.01）. Sperm vitality showed a downward trend, and the decrease in 1.0 mL group was extremely significant at 61-120 d（P＜0.01）, and significant at 121-180 d（P＜0.05）. 1.5 mL group decreased extremely significantly at 61-150 d（P＜0.01） and significantly at 151-180 d（P＜0.05）. The 2.0 mL group decreased significantly at 31-60 d and 151-180 d（P＜0.05）, and extremely significantly at 61-150 d（P＜0.01）.Sperm malformation rate increased, 1.0 mL group increased significantly from 31-60 d（P＜0.05）, 1.5 mL group and 2.0 mL group increased significantly from 1-60 d（P＜0.05）. utilization rates of fresh semen decreased, 1.0 mL group decreased not significant（P ＞0.05）, 1.5 mL group and 2.0 mL group was extremely significant decreased at 31-60 d and 1-60 d, respectively（P＜0.01）. The results suggested that different doses of foot-and-mouth disease vaccine had different effects on the fresh semen quality of different varieties of bulls, and the higher the injection dose, the greater effect on the quality of fresh semen.