Objective:MicroRNA (miRNA) expression is deregulated in many types of human cancers.We sought to investigate the expression patterns of the miRNAs,miR-21,miR-145 and miR-155 in sporadic gastric cancer in a Chinese population.Methods:Total RNA was extracted from archived gastric cancer tissues and adjacent non-cancerous tissues from 20 pairs of paraffin-embedded specimens.Expression levels of miR-21,miR- 145 and miR-155 were detected by quantitative reverse transcriptase PCR using a specific stem-loop primer,with U6 as the internal reference gene.Results:The expression of miR-21 and miR-155 in gastric cancer samples was significantly higher than in paired non-cancerous samples(P<0.05).There was no statistically significant difference in expression levels of miR-145 between cancerous and non-cancerous tissues(P>0.05).Conclusion:In Chinese sporadic gastric cancer tissues,the expressions of the oncogenic miR-21 and miR-155 were significantly up-regulated,while the expression of the tumor suppressor miR-145 was decreased,although this decrease was not statistically significant.Thus there is specificity in the miRNA expression pattern in gastric cancers in the Chinese population. Objective: MicroRNA (miRNA) expression is deregulated in many types of human cancers. We sought to investigate the expression patterns of the miRNAs, miR-21, miR-145 and miR-155 in sporadic gastric cancer in a Chinese population. Methods: Total RNA was extracted from archived gastric cancer tissues and adjacent non-cancerous tissues from 20 pairs of paraffin-embedded specimens. Expression levels of miR-21, miR-145 and miR-155 were detected by quantitative reverse transcriptase PCR using a specific stem-loop Primer, with U6 as the internal reference gene. Results: The expression of miR-21 and miR-155 in gastric cancer samples was significantly higher than in paired non-cancerous samples (P <0.05). Where was no resistance significant difference in expression Levels of miR-145 between cancerous and non-cancerous tissues (P> 0.05) .Conclusion: In Chinese sporadic gastric cancer tissues, the expressions of the oncogenic miR-21 and miR-155 were significantly up-regulated, while the expression of the tumor s uppressor miR-145 was decreased, although this decrease was not quite significant.Thus there is specificity in the miRNA expression pattern in gastric cancers in the Chinese population.