The symbiotic relationship between fruit flies and microorganisms has been a research focus at present. The Enterobacteriaceae are an especially important family of these symbiotic microorganisms, widely found in the gut and reproductive system of fruit flies. They play important roles in the carbon-nitrogen cycle, nutrition, metabolism, and reproductive immunity of their fruit fly hosts. Numerous enterobacteria have been identified by molecular techniques, and several metabolic products of enterobacteria enhance fitness. These findings can improve the efficiency of sterile insect technique (SIT). So, research on symbiotic enterobacteria is helpful not only to understand the interaction between fruit flies and symbionts, but also to exploit new control techniques of tephritid pests.