Abstract:The cyhalothrin, phoxim and endosulfan resistance levels of cotton bollworm, Helicover-pa armigera (Hubner) , collected from 16 locations in Round-Bohai Bai-Region from 1994 to 1997, were determined as 65.43 - 442, 10.28 - 90.93 and 6.34-29.17-fold, respe