Abstract： Objective:To explore CT imaging features related to disease-free survival (DFS) for gastric cancer (GC) patients with no clinical lymph node metastasis (cN0).Methods:From January 2005 to December 2018, 298 patients with GC were collected retrospectively in Peking University People′s Hospital. All the patients performed CT scanning before operation, and cT1-4N0M0 was defined by CT images. The clinical tumor stage (cT), extramural vessel invasion (EMVI), tumor morphological type, location and size were defined and recorded based on preoperative contrast-enhanced CT images. According to the pathological results, the patients were divided into pT1-2, pT3-4, pN0, and pN1-3 subgroups, with 148, 150, 135, and 163 cases, respectively. Progressive events and corresponding time were recorded during follow-up. DFS was defined as the time from radical operation to progressive events; if no progressive events occurred, DFS was defined as the time from radical operation to the last follow-up. The Kaplan-Meier curve and log-rank test were used to analyze the differences in cumulative DFS among patients with different CT imaging features, and Cox survival analysis was used to explore the independent CT imaging risk factors affecting DFS of cN0 patients. The log-rank test was used to test the effect of independent risk factors on cumulative DFS in different subgroups.Results:The follow-up time of enrolled patients was 36.0 (14.9, 59.3) months. The 3-year cumulative DFS rates of cT3-4 and cT1-2 GC patients were 61.2% and 85.6%, respectively, and the difference of DFS was statistically significant (χ 2=22.72, P<0.001). The 3-year cumulative DFS rate of EMVI-positive patients was 46.3%, which was lower than that of EMVI-negative patients (77.1%), and the difference was statistically significant (χ 2=21.34, P<0.001). There was no significant difference in 3-year cumulative DFS between different tumor locations and morphological types (χ 2=1.75, 1.73, P=0.189, 0.196). The difference in 3-year cumulative DFS between the tumor maximal diameter ≥3.4 cm and <3.4 cm groups was statistically significant (χ 2=17.58, P<0.001). On Cox survival analysis, cT (HR=5.203, P=0.001) and EMVI (HR=1.971, P=0.025) were independent risk factors for 3-year DFS in patients with cN0 GC. The results of subgroup analysis showed that the effect of EMVI on the 3-year DFS in pN0, pN1-3, pT1-2 and pT3-4 subgroups was statistically significant ( P<0.05). The effect of cT on the 3-year DFS was statistically significant in pN0, pN1-3, and pT1-2 subgroups ( P<0.05), but not in pT3-4 group (χ 2=2.58, P=0.108). Conclusion:cT and EMVI defined on preoperative CT examination are independently prognostic factors of 3-year DFS for patients with cN0 GC.