To investigate the relationship between gene p1 7 0 expression of human gastric carcino- ma tissues and histological types of the gastric carcinoma . 80 human gastric carcinoma tissues were taken from endoscopies and postoperations , and detected the p1 70 gene expression by peroxidase immuno- chemical stain method(Kit from US) . According to depth of yellow to brown stain on tumor cell mem- brane and/or cytoplasm ,if no colour stain indicated no p170 gene expression rif 70% stained 3+. The positive rate of p170 gene overexpression in gas- tric carcinoma tisaues by endoscopic . and postoperation were 66 % and 7 1% respectively. These histopathological types of gastric carcinomas with p 1 70 expression rate were 83% ( 5/6 ) in early carcino- mas ; 76% (26/34) in tubular adenocarcinomas ;64% (14/22) of undifferetiated adenocarcinomas ; 62% (5/ 8 ) in mucinous adenocarcinomas and 50% (2/4) in signet rign-form carcinomas. This study showed that p 1 70 gene overexpression gresented in human gastric carcinoma tissues and significantly in the group with metastatic lymph nodes. We considered that p 1 70 gene might be a new tumor marker for detection of gastric carcinoma.