The present study was conducted to investigate the developmental characteristics of Propylea japonica Thunberg (Coleoptera : Coccinellidae), a predator of aphids under laboratory conditions. The development times of the egg and immature stages of Propylea japonica were investigated at ten constant temperatures(15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35 and 38±1℃; 14L:10D; 60±5% RH). Development time was longest at 17.5℃. The developmental periods of P. japonica from the time of egg oviposited to adult emergence was 36.9 days at 17.5℃, and it decreased ash temperature increasing. Threshold temperature of development and degree days of the P. japonica from egg to adult were 11.9℃ and 196.0 respectively. The Briere 2 and Lactin 2 modes were best fitted for all development stages. The distribution of completion of each development stage was explain relatively well that 2-parameter, 3-parameter and Logistic model except egg and pupal stage.