Abstract：Objective To evaluate the therapeutic efficacy of oral hydrolyzed protein in the patients with gastrointestinal cancer. Methods Sixty cases of gastrointestinal cancer patients were prospectively included and then randomly divided into experimental group and control group; There were thirty cases in each group. The experimental group received routine nutritional support with daily oral 30g hydrolyzed protein; the control group only received routine nutritional support. Two groups accepted seven days continuous treatment. Hereafter we tested the related nutrition indicators and compared the differences between before and after treatment in two groups. Results During the treatment, the ratios of gastrointestinal complications in two groups were no significant difference. After nutritional support, the lymphocyte count, hemoglobin, total protein, albumin, globulin, pre-albumin, transferrin and HDL cholesterol in experimental group were higher than before treatment, but C-reactive protein was lower than before, the difference was statistically significant (P=0.031). However, compared with before treatment, only pre-albumin in control group was significant difference (P=0.028). After treatment, total protein, albumin, pre-albumin and transferrin in test group improved higher than control group (P=0.013, 0.001, 0.045, 0.048, respectively). Conclusions Common nutritional therapy, which combines with oral hydrolyzed protein in malnourished patients with gastrointestinal cancer, has a well adherence and tolerability and improves the patients' nutritional status.