Abstract: Objective: To evaluate the efficacy and safety of recombinant human interleukin-11 (rhIL-11) for treatment of chemotherapy-induced thrombocytopenia in the patients with gastrointestinal cancer. Methods: The monocentric, open and nonrandomization-controlled clinical study was conducted. When the platelet count was lower than 75×10⁹/L (degree- Ⅱ) after chemotherapy, a dose of 25μg/(kg·d) rhIL-11 was administered to the patients with gastrointestinal cancer, based on the standard of the NCI-CTC toxicity ranking in the observation ward. The regimen was used as a daily SC injection for 7 to 14 days. The chemotherapy-induced thrombocytopenia patients without administering rhIL-11 were randomly chosen as the paralleled controls. They were observed for 28 days. Results: Seventy-six cases were enrolled into this study, with 38 in both the treatment and the control groups respectively. It needed 8.1 days for recovery of the normal PLT value (≥100×10⁹/L) in treatment group, while in the controls the average recovery time was 12.2 days (P<0.01). Moreover, the mean recovery time from PLT≤50×10⁹/L to ≥100×10⁹/L was 8.9 days in treatment arm, while in control arm was 12.9 days (P<0.05). Major adverse events included edema, fever, articular muscle soreness, etc, but all were mild and well-tolerated. Conclusion: rhIL-11 can be safe and effective for treatment of the chemotherapy-induced thrombocytopenia in patients with gastrointestinal cancer.