Abstract: Body distribution and partial purification of acetylcholinesterase (ACHE) were investigated in cotton bollworm, Helicoverpa armigera (H(ibner). The head, thorax and abdomen possessed 78.2 96, 17.9 96 and 3.9 96 of total ACHE activities in the 7th-day adult, while in the sixth instar larva, the percentages were 90.3 %, 6.5 % and 3.2 % respectively. Eighteen times of the purified factors in ACHE ctivities were obtained by Sephardex G-200, but only four times by Sepharose 4B in column chromatography. The purified factors of ACHE were higher with Triton X-l00 than without Triton X-100 in eluant.

Key words: acetylcholinesterase, Helicoverpa armigera, insecticide resistance