Abstract: Objective To investigate the status of nutritional cognitive behavior and demand, and the occurrence of malnutrition in patients with inflammatory bowel disease(IBD). Methods A total of 135 patients with inflammatory bowel disease in Inpatient or Outpatient Departments of Second Affiliated Hospital of Nantong University were selected as research objects by convenience sampling method. The data of general data, disease activity index, body mass index(BMI)and nutritional status were collected. The nutritional cognition and behavior of IBD were investigated to understand the nutritional needs. The relationship between malnutrition and nutritional cognitive behavior was analyzed. Results Out of 135 patients, there were 11 patients(8.1%)with Patient-generated Subjective Global Assessment(PG-SGA)>4 points, and 7(5.2%)with BMI<18.5 kg/m². The correlation analysis showed that malnutrition was negatively correlated with effective dietary education in patients with IBD and was negatively correlated with the type of disease(r=0.506, P<0.05), abdominal surgery for IBO(r=0.517, P< 0.05), self-dietary restriction(r=0.532, P<0.05)and disease activity(r=0.558, P<0.05). Conclusion The cognitive behavior of dietary nutrition in patients with inflammatory bowel disease is not correct and reasonable, and the incidence of malnutrition is significantly increased. The patients have a high demand for nutritional guidance of medical staff, which should be paid attention to by clinical workers.