Abstract: A new bioassay method of residual film in glass tube was developed for the study of Diaphorina citri (Kuwayama) adult. The sensitivity of 4 field populations of D. citri to 6 insecticides was evaluated. The results indicated that the D. citri was susceptible to thiacloprid, thiamethoxam and chlorpyrifos with the resistance ratios in the range of (0.57-3.07)-fold. However, Lingchuan population in Guangxi Province developed moderate level of resistance to imidacloprid, with the resistance ratio of 18.90-fold. Meanwhile, Lingchuan population developed 9.72-fold resistance to lambda-cyhalothrin. Moreover, Lingchuan and Yongfu populations in Guangxi Province had developed low resistance levels to the novel insecticide sulfoxaflor, and the resistance ratios were over 5-fold. These results were in accordance with the reported documents about the control efficacy in field. It is helpful to set up a standard method to monitor the sensitivity dynamic of D. citri.