Abstract: Field studies indicated that there were eight generations of Campoletis chlorideae in a year in Xinxiang, Henan Province, of which six generations were spent in cotton fields. The occurrence of four generations coincided with that of early instar cotton bollworm (Heliothis armicreral larvae. Four peaks of bollworm parasitization by C. chlorideae were observed in mid-May, Mid- to late June, late July to early August, and late August to early September, respectively. Parasitization ranged from 19.2-42.9%, with the highest parasitization occurred in the 1st and 2nd host generations. The mean parasitic rate before the 3rd bollworm instar was 23.7% (max. 40.01%), which accounted for 71.3% of the total parasitization in a full host generation. The wasps were found to be sensitive to permethroids. The results showed that this parasitoid was the dominant natural enemy of cotton bollworm in northern Henan Province.