Abstract: Random amplified polymorphic DNA(RAPD)bacterial fingerrinting method was used for the genotype taxon of 72 strains of salmonella typhi(S.typhi)of phaye types M1,D2,E1 and D1 from Jiangsu Province among 1988～1997.The results showed that the isolates of phage type M1 were divided into seven genotypes.The 14 isolates from 1988 to 1991 were classified into seven genotypes,it suggests that the DNA polymorphism of isolates attributed to the epidemic of typhi in Jiangsu Province in the end of 80's and the begin of 90's.After 1992,the 91 67% (11/12)of the isolates were in the same group,the incidence of typhi were decreased in the same time.The genotype of D2 isolates were stable.The genetic pattens of E1 and D1 changed in the different years.Ths use of RAPD analysis enable us to recognise differences in DNA patterns among isolates of S.typhi of similar phage types and provide the epidemiological information more accurate and detailed.