Objective To evaluate the preoperative nutritional status of the patients which were preparing for cardiac valves replacement using nutrition risk screening 2002 (NRS2002),and analyze the evaluation effect and bring forward the corresponding nursing interventions.Methods 226 patients who would carry out cardiac valves replacement in the context of extracorporeal circulation were evaluated by NRS2002 preoperatively.88 patients had nutrition risk.Those elective 88 patients were randomly assigned into the experimental group and the control group,each had 44 cases.Then different nursing measures were implemented in each group and the clinical outcome was contrasted in the two groups.Results In the patients who were preparing for cardiac valves replacement,88 cases had preoperative nutrition risk score ≥3 points and 138 cases ＜ 3 points.Preoperative nutrition risk score had positive correlation with heart function grade.Difference of the experimental group and the control group in length of stay,length of mechanical ventilation after surgery and incidence rate of general complications had statistical significance.Conclusions It is effective to analyze the preoperative nutritional status of the patients with cardiac valves replacement by NRS2002.It may improve prognosis effectively by providing preoperative nursing interventions for patients with nutrition risk.Besides,it provides theoretical basis for further studying the relation between nutrition support and clinical outcome of patients with nutrition risk.