The incidence of malignant tumors of digestive system have accounted for about 1/3 of all malignant tumors so far, and become an enormous public health burden. Following lung cancer, digestive system malignancies have become the second leading cause of death due to cancer. Patients suffering from digestive system malignancies frequently have complication characterized by malnutrition, which have become a worldwide problem. Malnutrition is a continuous process which is easily ignored during hospitalization. Recently, accumulated studies have suggested that malnutrition had negative effects on both operation process and post-operation healing, which mainly attributed to poor clinical outcome. Considering the therapeutic strategy of malnutrition which includes early detection and intervention, it is of great importance to evaluate the nutritional status of patients with malignant tumors of digestive system in time. The review first introduced the definition and diagnosis of malnutrition followed by the elucidation of prevalence, causes and effects of malnutrition for patients with malignant tumor of digestive system. More importantly the review focused on elaboration of studies about malnutrition evaluation in methods, character and application status, as well as the summarizing the reports on APMT. This review introduces the definition and diagnosis of malnutrtion , and made a comment on the prevalence and causes and effects of the malnutrition for patients with malignant tumor of digestive system and the character and situation of the application with the common nutritional assessment methods home and aboard. And it also introduces the assessment of the thickness of adductor pollicis muscle from abroad.