Abstract:N-acyl-homoserine lactones(AHLs)are signal molecules in many gram-negative bacterias’ quorum sensing, called Autoinducer(AI). AiiA protein encoded by aiiA gene is involved in the degradation of AHLs, interfering the regulation process of bacterial quorum-sensing, restraining the induced expression of plant soft rot disease genes, and decreasing the virulence of bacterial pathogens. The essay summarizes the research situations of aiiA and AiiA, and the current application situations of aiiA in soft rot-resistant engineering bacteria and transgenic plant. The research directions are pointed out on the effective expression of AiiA proteins and improving plants’ soft rot-resistance.