Abstract: OsRwp34 was isolated in a cDNA library which was constructed from rice(Oryza sativa) seedling under high temperature(45℃) stress.In order to study the function of OsRwp34,we constructed an expression vector pET-28(a)OsRwp34 which included OsRwp34 gene and transformed it into the E.coli strain BL21(DE3).The bacteria was incubated in LB medium and induced by IPTG,and the host bacteria was found to be dying rapidly in 30 min through the OD600 monitor and quantitative plating,The result suggested that the expression product of OsRwp34 caused the death of the bacteria.Continuously,three deletion mutants,one of them deleted 15 aa of N terminate,the other two deleted 12 aa and 47 aa of C terminate respectively,were constructed.But the toxic effect to the bacteria growth was not found after the induction of IPTG.It indicates that the exist of both N and C terminates are necessary for the toxic effect of OsRwp34.A further study will be required on the toxic mechanism of OsRwp34.