Abstract:The damaged species of root-knot nematodes to plants in Shandong Province were investigated, and nematodes from four typical regions(Tai‘an Shandong Agriculture University, Tai‘an Liangzhuang, Shouguang Zhuangjia and Shouguang Xujia) with different pesticides-used levels were collected. The nematodes were identified using morphological characters and esterase phenotype, sensitivity of the second instar larvae to avermectin and phoxim were compared, and the distinctions between different protective enzymes associated with resistance were determined. The results showed that the nematodes belong to Meloidogyne incognita, which damaged 51 species of vegetables and accounted for 66.2% of all the investigated plants. The sensitivity ratios of second instar larvae were 0.97 to 1.23 to avermectin, and 0.94 to 1.10 to phoxim. Although there were no significant differences in sensitivity to tested pesticides, the trend of sensitivity declining with longer and higher the chemical agents used was shown. From the biochemical level, the female nematodes of the four regions had subtle differences in soluble protein, while the POD and SOD isozymes had no significant differences.