Abstract: The study shows that the mating peak of the overwintering generation adults of Ancylis sativa appeared at 6.0～8.0 hours in their scotophase and the mating activity was more intensive during 2～3 days after eclosion.The higher the temperature was, the later the adults began to mate.For mostadults, the duration of mating was 3～4 hours,with a mean frequency of 3.3 times for males and 1.59 for females.The mating behavior of 2-days old adults shifted from photoperiod 14L◇10D to continuous dark was similar to that at 14L◇10D,all showing an obvious rhythm.When the adults were shifted to continuous light,their mating became inacitive and irregular.The sex pheromone titer of virgin female decreased significantly after mating l hour,and remained low until 48 hours after mating.