Abstract: KISS-1 plays a pivotal role in the regulation of animal reproduction，thus this study is aimed to investigate the role of KISS-1 gene in regulating seasonal reproduction of the yak. Samples of hypothalamus，pituitary etc. were collected from five adult female yaks and five yellow cattle. KISS-1 gene sequence and its tissue expression characteristics were studied by RT-pcr and qPCR techniques. The results showed that the coding region length of yak and yellow cattle KISS-1 gene was 408 bp，which encoded 135 amino acids，and there were 7 base mutations between these two species. The amino acid sequence identities of yak KISS-1 gene with yellow cattle，Tibetan goats，sheep，wild pig，human，and sewer rat were 97.1%，85%，65%，55%，and 51.5% respectively. Expression of KISS-1 gene was detected in hypothalamus，pituitary，ovary，fallopian tube，and uterus of yak and cattle. The expression levels in hypothalamus and pituitary were the greatest，but there was no significant difference between the two species（P > 0.05）. It is concluded that KISS-1 gene is conservative in animal evolution，and its regulation roles in seasonal reproduction of the yak need to be further studied.

Key words: yak, yellow cattle, KISS-1, sequence analysis, tissue expression