Objective:To evaluate the clinical efficacy and prognostic factors in patients with stage Ⅲb/c or Ⅳ inoperable advanced gastric cancer.Methods:The clinical data of 33 patients with unresectable locally advanced (stage Ⅲb/c) or unresectable stage Ⅳ gastric cancer were collected from May 2017 to may 2019 in the Department of Surgical Oncology, Anqing Hospital affiliated to Anhui Medical University, Among them, there were 25 males and 8 females with an average age of 65.48±9.00 years. According to the data of patients with conversion therapy efficacy and postoperative pathology and other factors for statistics, using univariate and multivariate analysis method to evaluate its correlation with the prognosis of patients.Results:Of 33 patients, 2 patients were complete remission, 18 patients were partial remission, the objective response rate(ORR) was 60.6%. 20 patients recevied surgical treatment, 17 patients achieved R0 resection. The median overall survival(mOS) of all 33 patients was (18.6±4.5) months. The mOS of patients who underwent surgical treatment was (25.7±10.99) months, which in patients without surgical treatment was (11.2±2.5) months( P=0.004). The mOS of stage Ⅲb/c patients Was (18.9±10.99) months, and of stage Ⅳ patients was (11.3±0.35) months( P=0.568). Univariate analysis showed that preoperative chemotherapy cycle ≥4 weeks had a better prognosis than patients with less than 4 cycles ( P=0.003), TRG score 1/2 patients had a better prognosis ( P=0.001), and positive lymph nodes ≥7 was risk factor. Multivariate analysis showed that positive lymph nodes ≥7 was the only independent prognostic factor ( P=0.013). Conclusion:For patients with stage Ⅲb/c or Ⅳ inoperable advanced gastric cancer, surgical resection after conversion therapy can improve patient survival, adequate preoperative chemotherapy can improve the prognosis of patients with at least 4 cycles of chemotherapy.