Abstract: Objective: To investigate the relationship between the expression of RASSF1A in human primary gastric adenocarcinomas and the infection of Helicobacter pylori(Hp).Methods: The mRNA expression of RASSF1A was determined by reverse transcription polymerase chain reaction(RT-PCR) in 48 cases of primary gastric carcinoma and 15 matched normal tissues.Hp was examined in 48 cases of gastric carcinoma by polymerase chain reaction(PCR) technique.Results: The rate of loss of RASSF1A mRNA expression in 48 primary gastric carcinomas was 52%(26/48),and positively related with histological differentiation degree(P<0.05),lymph node metastasis(P<0.05) and TNM stages(P<0.05).There was no relationship between RASSF1A expression and Hp infection(P>0.05).Conclusions: RASSF1A is a related tumor suppressor gene of gastric carcinoma,it is closely correlated with the tumor clinical pothological stage and the histological differentiation degree.There is no relationship between RASSF1A expression and Hp infection,both are probably independent etiological factors.