Abstract: Parocneria orienta Chao is considered to be the most destructive insect pest in cypress forest in Sichuan Province, and the overwintering generation had obvious diapause phenomenon. In this paper, effects of temperature and photoperiod on diapause induction and termination of Parocneria orienta Chao were studied through artificial induction method. The results showed that: (1) Temperature had a significant effect on diapause rate of Parocneria orienta Chao (P<0.01). The diapause rate gradually increased with the decrease of temperature; (2) Temperature and photoperiod had synergistic effect on the diapause of Parocneria orienta Chao. Temperature played a major role and photoperiod played a subsidiary role. When the ambient temperature was below than 25 ℃, short daylength light could promote the induction of diapause, and there were significant differences in diapause rate of Parocneria orienta Chao under different photoperiod conditions (P<0.05); (3) 25 ℃ condition was most favorable for diapause termination of Parocneria orienta Chao. Photoperiod had no significant effect on diapause termination.