Objective: To investigate the miR-155 expression in gastric cancer tissues and its clinical relevance. Methods: The surgical specimens of 52 cases of stomach cancer and their adjacent normal tissues were collected. The miR-155 expression level in gastric cancer and adjacent normal tissues were determined by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) technique, and the relations of miR-155 expression with the clinicopathologic factors of gastric cancer were analyzed. Results: The RT-PCR results showed that the miR-155 expression value in gastric cancer tissues (0.84±2.27) was significantly higher than that in their paired adjacent normal tissues (0.28±0.56) (P<0.05). The miR-155 expression level was associated with the lymph node metastases in gastric cancer patients, the miR-155 expression in patients with the lymph node metastases was higher than that in those without lymph node metastases (P<0.05). The miR-155 expression level was irrelevant to the sex, age, tumor size, depth of invasion, and all the differences between the groups on these factors had no statistical significance (all P>0.05). Conclusion: miR-155 has high expression level in gastric cancer tissues, and it may be relevant to gastric cancer lymph node metastasis.