A glass vial technique was developed to estimate the insecticidal activities of some organophosphorus, carbamate, pyrethroid and (OP + IGI) insecticides to both pink and spiny bollworms. Also, monitor of field populations for resistance to tested insecticides was followed. Respons­es of susceptible strain were compared with those collected from the fields at Kafr EI-Dawar . El-Bouheira Governorate during 1997 and 1998 . Data indicated high resistance levels to the pyrethroid fenvalerate, the OP chlorpyrifos and the carbamate thiodicarb and to the two insecti­cides11G1 mixtures namely delfos and empire in pink bollworm field strain showing a: 34.84, 101.4, 105.5, 104.6 and 129.58 fold, of resistance, respectively. While spiny bollworm was in the tolerant stage with : 3.31, 2.81, 2.75, 3.89 and 3.45 folds, respectively. The calculated LC90 from Lc-p lines were used as discriminating concentration to determine resis­tance in both PBW and SBW in 1998.