Abstract: The quantitative structure activity relationship (QSAR) of the insecticidal activities of 28 m-phenoxybenzyl oxime-ethers and 30 biphenylbenzyl oxime-ethers against Nephotettix cincticeps using comparative molecular field analysis (CoMFA) method was investigated. Separate studies of QSAR models on each set of compounds and whole set of compounds were carried out. Three models show that p-substituent on phenyl ring of oxime moiety is the main factor affecting the activity. The larger volume and stronger electricity p-substituent has, the higher activity the compound has. By comparing these 3 models, it is found that the integrated model shows a higher ability to predict the activities of these oxime-ethers than other models, crossvalidated R2cv=0.628, non-crossvalidated R2=0.971, standard error(SE)=0.109, F=133.84. The integrated model also shows a high ability to predict the biological activity(-lgLC50) for 10 testing set compounds. QSAR models will give some guidance on synthesizing compounds with enhanced activities.