The present study was aimed to examine the effect of different host plants on the biological property of cotton caterpillar, outbreak pest of cucurbit vegetables. The feeding and oviposition preferences toward cucumber and pumpkin were greater than those toward watermelon, oriental melon, and melon. The periods of egg and larva fed on oriental melon, melon, and pumpkin were longer than those on watermelon and cucumber. The longest pupal period was 10.5 days from cucumber. The hatching rate, pupation rate, emergence rate, and survival rate were observed from different host plants. The hatching rate was the highest on cucumber (87.2%) and the lowest on melon (72.8%). The pupation rate on watermelon and oriental melon (90.0% and 89.1%, respectively) was higher than that on cucumber (62.0%). The emergence rate on cucumber and pumpkin (93.5% and 92.0%, respectively) was higher than that on oriental melon (78.7%). The survival rate from hatching to emergence on watermelon (76.0%) was the highest, and the lowest on cucumber (50.0%). The adult period on melon (21.0 days) was the longest, and the shortest on cucumber (15.5 days) among 5 host plants. Average number of eggs per female on cucumber (281.8 eggs) was the highest, and the least on oriental melon (96.6 eggs). The survivorship on cucumber was the longest (30 days), and the shortest on pumpkin (17 days). The preoviposition period on oriental melon and melon (3.4 days) was longer than that on watermelon (2.1 days) and mean generation time in day (T) on melon was the longest (47.2 days) though they were not significant. The net reproductive rate per generation (R) on cucumber, 191.3, was the highest and the highest intrinsic rate of natural increase (r) was observed from cucumber as 0.127. All these results suggest that the growth ana reproduction of cotton caterpillar varies depending upon the kind of host plants. The analysis of the life table revealed that cucumber and pumpkin were the favorable host plants of cotton caterpillar.