[Objectives]  To detect the infection of Bemisia tabaci by Rickettsia, and the distribution and dissemination of Rickettsia after its transmission to cowpea leaves through whitefly feeding. [Methods]  Infection of the B. tabaci Q biotype by Rickettsia, and its persistence in cowpea plants, were detected by PCR and fluoresent in situ hybridization (FISH). [Results]  The distribution of Rickettsia was limited to the phloem vessels of cowpea leaves, Rickettsia could move along the vessels between different leaves, and its efficiency of dissemination was highly related to the initial population size of Rickettsia-positive B. tabaci individuals that fed on the cowpea leaves. Phylogenetic analysis based on 16S rRNA variation showed that Rickettsia in cowpea plants and whiteflies was 100% identical. [Conclusion]  Rickettsia can be horizontally transmitted to cowpea plants through the feeding of the B. tabaci Q biotype and  little genetic variation appears to be associated with horizontal transmission from insect to host plants.