Abstract: ObjectiveTo explore the relationship between the genetic types of helicobacter pylori and diseases.MethodsRandom amplification polymorphic DNA(RAPD)method and polymerase chain reaction-restriction fragment length polymorphism(PCR-RFLP)method were used to analyze 50 isolates of Hp from different patients,then the cluster analysis was used to classify these isolates and a case-control study was used to explore the relationship between the genetic types of helicobacter pylori and different diseases.ResultsThe results of RAPD showed that the genetic types of helicobacter pylori had the relationship with different gastrointestinal diseases.The results of PCR-RFLP can't show this relationship in the level of a single gene,but this relationship was also showed in the level of multiple genes.The results of RAPD and FCR-RFLP were combined to be analysed,which indicated that the genetic types of helicobacter pylori had the relationship with different outcome of diseases in the level of the multiple methods.ConclusionThe numerical classification of the multiple gene was better than the typing method of a single gene.This would become the basis of building numerical typing system of Hp using multiple genes and multiple methods.