AIM: To evaluate the significance of hsp90α expression in human gastric cancer tissues.METHODS: Immunohistochemical staining was used in clinical specimens from 33 cases of gastric cancer and 33 cases of gastritis with rabbit anti-human hsp90α multi-clonal antibody in order to explore the relationship between the expression of hsp90α in gastric carcinoma tissue and gastritis tissue as well as in mucous membrane adjacent to cancer and lymph node metastasis.RESULTS: Hsp90α was detected in 88 % of gastric carcinoma cases and 55 % of gastritis cases. The hsp90α positive rate in gastric cancer group was significantly higher than that in gastritis group (P＜0.01, P=0.005). The hsp90α positive rate in gastric cancer and in mucous membrane adjacent to cancer was 88 % and 55 % respectively (P＜0.01,P=0.005). The hsp90α positive rate in lymph node metastasis group and non-lymph node metastasis group was 100 % and 60 %respectively, and a significant correlation between hsp90α expression and lymph node metastasis was shown (P＜0.01,P=0.005).CONCLUSION: The hsp90α expression rate in gastric cancer group was significantly higher than that in gastritis group as well as that in the group of mucous membrane adjacent to cancer. The hsp90α expression in lymphatic node metastasis group was higher than that in non-lymphatic node metastasis group. The results indicate that increased hsp90α expression has a close relationship with occurrence and lymph node metastasis of gastric cancer.