Objective To explore the incidence of sarcopenia and its influencing factor in patients with malignant gastrointestinal can-cer. Methods A total of 166 patients with malignant gastrointestinal cancer were selected by using convenient sampling, their appendicular skeletal mass were measured and their basic information, nutritional status were investigated within 12 hours after admission. Results The incidence of sarcopenia in the participants was 19.88%, and their incidence of nutritional risk and malnutrition was 57.23% and 50.60% respectively.The result of logistic regression analysis showed that, nutritional risk, the number of chronic diseases, percentage of body fat were influencing factors of sarcopenia (all P＜0.05). Conclusion The incidence of sarcopenia is high in preoperative patients with malignant gastrointestinal cancer.Medical staff should identify the high-risk population of sarcopenia in time, so as to take suitable action to improve the prognosis of patients, such as adding essential amino acids, approp-riately increasing muscle mass and reducing fat mass, etc.