Abstract: In order to study the effect of cryopreservation time on the semen motility characteristics of Lin horses and the conception rate of mares during estrus, the experiment used citric acid-fructose-Tris-glycerol-yolk as the diluent. In the experimental group, fresh semen and semen stored at low temperature （4 ℃） for 24, 48, 72, 96, and 120 h were collected, and the sperm motility characteristics were detected by conventional sperm quality testing methods. The results showed that compared with fresh sperm, motile sperm motility, forward motility sperm motility, average motility rate and fast motility sperm motility decreased with the prolongation of storage time. When the semen was stored at low temperature （4 ℃） for 0, 24, 48, and 72 h, the estrus conception rates of Jilin horse mares after artificial insemination were 43.33%, 44.00%, 44.45%, and 43.48%, respectively, with no significant difference （P>0.05）. However, after 96 h and 120 h storage, the estrus conception rates of Jilin horse mares after artificial insemination were 36.00% and 10.00%, respectively （P<0.05）, indicating that the effective storage time of Jilin horse semen at low temperature （4 ℃） cannot exceed 72 h.

Key words: Jilin horse, cryopreservation time, sperm motility, artificial insemination, estrus conception rate