Assess the different nutritional status between admission and discharged in older adult patients using the GLIM criteria.A retrospective analysis was conducted on a multicenter study which initiated in 34 hospitals in China with 2734 hospitalized older patients. The dynamic changes of malnutrition according to GLIM criteria were performed between at admission and discharge, and their significance was analyzed using the chi-square test. The association between malnutrition and clinical outcomes was analyzed using the chi-square test, t-test, or rank sum test, and divided into different disease types for further analysis.The incidence of nutritional risk in elderly patients was 51.6% at admission and 48.4% at discharge. The prevalence of malnutrition according to the GLIM criteria was 19.6% at admission and increased to 33.4% at discharge, which was significantly different. Different age and disease type were related with nutrition status. Malnutrition is significantly association with adverse clinical outcomes such as increased risk of complications and prolonged length of hospital stay.The GLIM criteria can be used in elderly patients to assess malnutrition. The prevalence of malnutrition in elderly inpatients is high, and the prevalence of malnutrition at discharge is higher than that observed at admission. Attention should be paid to the dynamic changes of malnutrition in elderly patients during hospitalization.