Abstract: Random amplified polymorphic DNA bacterial fingerprinting method was used for the genotype taxon in 26 strains of phage type M1 of salmonella typhi (S.typhi) isolated from different areas in Jiangsu Province during 1988-1997. The results showed that all isolates were divided into seven genotypes. The 14 isolates from 1988 to 1991 were classified into seven genotypes. It was suggested that the DNA polymorphism of isolates attributed to the epidemic of typhi in Jiangsu Province in the end of 80's and the beginning of 90's.After 1991,the 91.76%(11/12)of the isolates were in the same group.The incidence of typhi were decreased in the same time.Random amplified polymorphil DNA fingerprinting method was a rapid and powerful tool for the genetic characterization of S.typhi.