Abstract: The study compared the effects of different thawing temperatures （5， 15， 40， 75， 90℃） and times（1-120 s） on properties of post-thaw cow semen by detecting frozen-thawed semen motility， acrosome integrity and tail membrane integrity. The results showed that motile spermatozoa rate of frozen semen thawed at 75℃ for 3 s was the highest. A similar result was observed under thawing at 40℃ for 20 s. Under 5℃ and 15℃ thaw sperm motility was lower. Sperms defrosted at 90℃， the acrosome integrity and tail membrane integrity were significantly lower than those at 40℃（P<0.05） and 75℃（P<0.01）， and the sperm deformity rate was significantly higher than that treated at 40℃ and 75℃（P<0.05）. With the increasing of thawing temperature， the sperm effective survival time at 37℃ showed significant difference as 40℃>75℃>90℃. In conclusion， it was recommended that the frozen semen thawing at 75℃ for 3 s could be used for artificial insemination immediately. When a large number of cows need to be inseminated or thawed semen could not be inseminated immediately， in order to keep the sperm vitality for a longer time， the frozen semen thawing at 40℃ for 20 s would be suitable.

Key words: cow semen, thawing temperature, thawing time, semen quality