Abstract: In order to explore the effects of mating in the different seasonal temperature conditions on reproductive performance of sows， we made a statistical analysis of sow reproductive record of a Zhejiang pig farm in recent three years. The results showed that: the parturition rate and the number of live born of sow mating in summer is the lowest （69.67%， 8.34）， which reduced by 5.06%， 4.04%， 4.62% and 0.21， 0.65， 0.82 compared with that in spring， autumn and winter respectively. The average birth weight of piglet born in spring after sow mating in winter was 1.34 kg， which increased by 0.19， 0.12 and 0.07 kg. The rearing rate of piglet born in spring after sow mating in winter was in a high level （85.31%）， next to piglet born in summer after sow mating in spring(88.86%). Therefore， the temperature has a great influence on reproductive performance of sows， and the optimal mating season is in winter．

Key words: seasonal temperature, mating, reproductive performance