Objective To assess the effect of preoperative enteral nutrition on malignant digestive tumors patients with nutritional risk. Methods A prospective clinical study was conducted on 73 malignant digestive tumors patients who were admitted in Department of General Surgery, Peking Union Medical College Hospital from January to June in 2015. Seventy-three patients were screened preoperatively by NRS 2002 and then divided into two groups: enteral nutrition group (n=31) and control group(n=42). Patients in enteral nutrition group were given oral or tube feeding elemental diet for 7-10 days before operation. Patients in control group ate normally. Both patients were given intravenous nutritional support postoperatively. The data of body weight, body mass index, blood total protein, albumin, pre-albumin and incidence of postoperative complications were compared on admission and before operation.Measured data were expressed as ±s. The t-test was used to compare the indexes between groups. The paired t-test was used for comparison between admission and before surgery; the count data were expressed as frequency and percentage (%), comparison between groups use Chi-square test or Fisher′s exact probability method. Results The nutritional status including body weight, body mass index, blood total protein, albumin and pre-albumin were significantly improved pre-operatively in enteral nutrition group(P 0.05). Conclusion Pre-operative enteral nutrition is safe and efficacy, which is helpful for malignant digestive tumors patients with nutritional risk. Key words: Digestive system; Neoplasms; Nutritional risk; Enteral nutrition