Abstract: Bismark brown staining method and immunohistochemical method were used respectively for the observation of mast-cell (MC) and C-erbB-2 oncoproteins in 57 cases of gastric carcinoma. The results showed that:(1)MC counts were related to the differentiation and metastasis of gastric cancer, in the high and moderate differentiation tumors, MC counts were higher than in the low and undifferentiated ones (P＜0.05) and in the metastatictumours they were lower than in the nonmetastatic ones (P＜0.05). (2) C-erbB-2 oncoproteins were not related to the differentiation and metastasis of gastric cancer (P＜0.05).(3) The positive expression of C-erbB-2 oncoproteins were related to MC counts of gastric cancer, high MC count groups were inferior to low MC ones (P＜0.05).