This study was carried out to investigate the effect of heparin, CSA and PC12 on sperm motility and acrosome reaction in bovine fresh and frozen semen which were washed and incubated in mTALP, and also the effect of heparin-pretreatment on motility and acrosome reaction in mTALP, and also the effect of heparin-pretreatment on motility and acrosome reaction of sperm treated with PC12, and the results obtained were as follows : 1. When fresh sperm was once washed and then incubated for 15 minutes in mTALP containing heparin 1, heparin 2, CSA and PC12, the percent of motile sperm of PC12 was significantly lower than that of control, heparin 1, heparin 2 and CSA. But the percent of acrosomereacted sperm of PC12 was signifciantly higher than that of control, heparin 1, heparin 2, and CSA. 2. When frozen sperm was once washed and then incubated for 15 minutes in mTALP containing heparin 1, heparin 2, CSA and PS12, there was no significant difference in the percent of motile sperm among treatments, but the percent of acrosome-reacted sperm of PC12 was signifciantly higher than that of heparin 2, and there was no significant difference in the percent of acrosome-reacted sperm among control, heparin and CSA. 3. When fresh sperm was twice washed and then incubated for 15 minutes in mTALP containing heparin and PC12, there was no significant differrence in the percent of motile sperm among treatments, but the percent of acrosome-reacted sperm of PC12 was significantly higher than that of control and heparin. When the sperm was incubated for 120 minutes, the percent of motile sperm of PC12 was significantly lower than that of control and heparin, but the percent of acrosome-reacted sperm of PC12 was significantly higher than that of control and heparin. 4. When fresh sperm was twice washed and preincubated in mTALP containing heparin for 0, 15, 120, and 240 minutes, and then incubated with PC12 for 15 minutes, there was no significant difference in the perce수 of motile sperm among treatments, but the percent of acrosome-reacted sperm of 120 and 240 minutes was significantly higher than that of 0 and 15 minutes.