Objective To knock down angiopoietin-1 expression in human gastric cancer cell line BGC-823 and to observe its effect of reversing tumor invasion. Methods siRNA sequence fragments was designed to target angiopoietin-1 and transferred into human gastric cancer cell line BGC-823. RT-PCR was used to assess the transcription level of angio-poietin-1 mRNA, then western blot and immunofluorescence were used to examine the expression level of three invasion-as-sociated proteins include integrinβ1, CD44V6 and Ang-1. Cell adhesion ability was evaluated by cell adhesion assay and cell invation was determined by matrigel and transwell plastic dual-chamber culture system. Results Ang-1 mRNA was knocked down by siRNA showed by RT-PCR. The expression of integrinβ1, CD44V6 and Ang-1 were significantly lower than control group(P<0.05), so did the cellular adhesion and invasion abilities(P<0.05). Conclusion Knocking down angiopoietin-1 by siRNA can reverse invasion of human gastric cancer cell line BGC-823 and may provide new ideas and reference for gene therapy of gastric cancer in the future.