【Objective】To clarify the best feeding sites and the shortest time of Diaphorina citri Kuwayama in spreading Huanglongbing（HLB）and to provide guidance for the prevention and control of HLB.【Method】The bacterium acquisition efficiency of D. citri was tested by PCR， which had been fed on three different parts： tender shoots， mature leaves and old leaves of infected Citrus reticulata Blanco. cv. Mashuiju and Citrus sunki Hort. ex Tanaka for 24 h. 【Result and conclusion】The results showed that the infected rates of D. citri were significantly different among the three parts of C. reticulate. The infected rate on mature leaves was the highest and old leaves was the lowest. The bacterium acquisition efficiencies were also different among the three parts of C. sunki. The infected rates of old and mature leaves were both significantly higher than those of tender shoots. There was no significant difference between the old and mature leaves. The bacterium acquisition efficiency of D. citri feeding on tender shoots of C. reticulate was significantly higher than that on C. sunki， while on old leaves of C. sunki were significantly higher than that on C. reticulate， and there was no significant difference between the 2 species when feeding on mature leaves. The two hosts had the same infected rate of 36.67% when compared feeding on the whole plants.