Citrus reticulata cv. chachiensis, also known as Xinhui Mandarin Orange, has a long history of cultivation in Guangdong (Xinhui) and is a local agricultural product in Guangdong. There are no relevant studies on the symptoms description and distribution of Candidatus Liberibacter asiaticus (CLas) in C. reticulata cv. chachiensis infected with Citrus Huanglongbing (HLB). Through this study, it can provide a basis for the study of the movement of CLas in citrus plant branches and fruit pith and can also provide ideal plant materials for the subsequent acquisition of high concentration of CLas. In this study, C. reticulata cv. chachiensis branches and fruit pith infected with CLas were used as plant material to identify symptoms and analyze the distribution of CLas in different parts of citrus branches and different length fragments of the fruit pith based on real-time quantitative PCR (qPCR). Through the observation of the leaves and fruits from the infected citrus plants, the upper leaves of the branches infected with CLas showed mottled and element-deficient yellowing, especially the symptoms of the new leaves of the branches were more obvious, while the color of the lower old leaves was dark green and the texture was hard. Compared with the healthy fruit, the fruit infected with CLas showed uneven coloring, showing typical symptoms of "red nose fruit". Meanwhile, compared with the healthy fruit, the fruit infected with CLas showed uneven size, abnormal body and asymmetrical shape, the seed was small and the seed aborted. The concentration of CLas in the central axis of the fruit was close to that in the fruit pith, and significantly higher than that in other parts of the branches (P<0.05). CLas was also unevenly distributed in different length segments of the same fruit pith, and the concentration of CLas was the highest in the middle of fruit pith (1-3 cm fragment), the concentration of CLas in the central axis and fruit pith of HLB-infected C. reticulata cv. chachiensis fruits is significantly higher than that of other parts. The study could be a reference for the identification of HLB, a basis for the study of the movement of CLas in citrus plant branches and fruit pith, and used to select ideal plant materials for the subsequent acquisition of high concentration of CLas.