Objective:To evaluate the effect of preoperative neoadjuvant chemotherapy regimen of XELOX (capecitabine combined with oxaliplatin) on surgical condition and oncogene expression in advanced gastric cancer.Methods:From January 2015 to July 2016, 124 patients with advanced gastric cancer who were admitted to our hospital were selected. Random number table method was used to divide them into an observation group and a control group, 62 each group. The observation group received two courses of neoadjuvant chemotherapy (XELOX) before operation, and the control group received surgery. The operation condition, expression of oncogenes in gastric cancer lesions, occurrence of adverse reactions and the long-term prognosis were compared between the two groups.Results:The R0 resection rate of the observation group was significantly higher than that of the control group, and the difference was statistically significant (P<0.05). The operation time of the observation group was shorter than that of the control group, the amount of intraoperative bleeding and the amount of postoperative drainage of the observation group were less than that of the control group, and the differences were statistically significant (P<0.05). The mRNA expression of gastrokine 1, multiple tumor suppressor protein, Wilms tumor gene on the X chromosome (WTX gene) and gene of phosphate and tension homology deleted on chromosome ten (PTEN gene) in the observation group after treatment was significantly higher than that in the control group before treatment, and the increase amplitude of the observation group was more obvious than that of the control group (P<0.05). There was no significant difference in the incidence of adverse reactions between the two groups (P>0.05). In terms of long-term prognosis, the disease-free survival time and average survival time of the observation group during the two-year follow-up period were significantly better than those of the control group, and the recurrence rate of the observation group was significantly lower than that of the control group; the differences were statistically significant (P<0.05).Conclusion:Preoperative XELOX for advanced gastric cancer patients can effectively increase the proportion of radical surgery, reduce the risk of surgery, and significantly regulate the expression of oncogene, thus improving the long-term prognosis of patients.