Objective To explore the effect and safety of preoperative impact chemotherapy in the treatment of advanced gastric cancer patients.Methods 104 patients with advanced gastric cancer were randomly divided into two groups,including 54 cases of observation group,54 cases of control group.The observation group was given modified FOLFOX7 regimen for 2 courses before operation,and 6 courses FOLFOX7 regimen after operation.The control group was given routine operation and FOLFOX7 regimen for 8 coures.The effective rate,l-year,2-year,3-year survival rate and toxic effects after operation were observed.Results In observation group,the effective rate was 59.3％,the curative resection rate was 81.5％,and the overall resectability rate was 90.7％,and those was 35.2％,59.3％,75.9％ in control group,all the difference was statistically significant( x2 =8.55,6.39,4.27,all P ＜ 0.05 ).The 1 -year,2-year survival rates after operation were not significantly different ( x2 =0.38,2.06,all P ＞0.05 ),while the difference was significant at 3-year after operation( x2 =4.06,P ＜ 0.05 ).There was no significant difference on the toxic effects between the two groups ( P ＞ 0.05 ).Conclusion Modified FOLFOX7 regimen is effective and well-tolerable for patients with advanced gastric cancer,and it could contribute to improve the overall resectability rate and survival rate after operation.