To investigate the effect of short photoperiod on hormones that related to hair growth in Inner Mongolia (Arbas type) Cashmere goat,six pairs of 2yearold twins ewes were selected from the short photoperiod and control group.The blood samples were collected and content of hormones were determined by enzyme linked immunoassay.SAS9.0 software was adopted to conduct significant test and correlation analysis.The results showed that the content of MLT and IGF1 was significantly increased,the content of PRL was significantly decreased,and the content of EGF and GH was not significant different between the two groups under short photoperiod in a day.In a year,the content of MLT (P<0.05),IGF1 and EGF (P>0.05) was increased,and the content of PRL (P<0.05) was significantly decreased under short photoperiod in June.The content of MLT,IGF1 and GH was significantly higher (P<0.05),and the content of PRL was lower in the experimental group than in the control group,in September.The correlation between PRL and other hormones in both groups was negative.Compared with the control group,interactions between MLT and PRL/EGF,between PRL and IGF1/EGF/GH,between IGF1 and EGF/GH,between EGF and GH (P>0.05) were increased,and interactions between MLT and IGF1/GH were decreased under short photoperiod.In conclusion,the short photoperiod might enhance hair growth by synergistic and antagonistic effect of hormones that related to hair growth