By definition, endosymbionts reside in the hosts' cells and are maternally inheritted to offspring as the mitochondriondoes. Recent progresses reveal that some endosymbionts have evolved their manipulabilities of hosts' reproduction. Inthis nature, once an endosymbiont shares its host with others, their association may last long unless their evolutionaryinterest or hosts' fitness is undermined.We tested whether the association existed among the endosymbionts; Wolbachia, Spiroplasma, Cardinium and Rickettsia.The results show that there are some multiple infection cases but there is no obvious pattern in their association.