Abstract: ObjectiveTo determine the expression level of long non-coding RNA (lncRNA) imprinted maternallyexpressed transcript （H19） in colorectal cancer tissues and its effect on proliferation of colorectal cancer SW620 cells. MethodsReal-time quantitative PCR (qRT-PCR) was applied to detect the expression of H19 in 20 paired tumor tissues and adjacent normal tissues, and in normal NCM460 cells and colorectal cancer SW480, HCT116 and SW620 cells. The specific small interfering RNA for H19 (si-H19 group) or negative control sequence (si-NC group) were transfected into SW620 cells. Proliferation of the transfected cells was detected using flow cytometry, CCK8 assay and clone formation experiment. The expressions of CyclinD1 and cyclin dependent kinase 4 (CDK4) were detected by qRT-PCR and Western blot. ResultsThe expression levels of H19 in colorectal cancer tissues and cells were higher compared with those in adjacent normal tissues and normal NCM460 cells. Lower H19 level, cell activities and cell clone numbers were found in si-H19 transfected cells compared with those in si-NC transfected cells ( P<0.05). si-H19transfected cells had decreased expression of CyclinD1 and CDK4 ( P<0.05). ConclusionH19expression in colorectal cancer is high. Knock-down H19 expression can inhibit proliferation of colorectal cancer cells, which provides a potential strategy for targeted therapy of colorectal cancer.