Objective To determine,the clinical significance of serum myocardial enzymes (Mb,cTNI, CK,CK-Mb,AST,LDH) in the classification of the disease severity of non-cardiogenic critically-ill patients. Compared with APACHEⅡscore concerned as the standard diagnosis of the critical ills,these biomarkers were investigated for the evaluation possibility of the degree and the prognosis of the critical ills.Method Patients admitted to our EICU were consecutively collected for the research from April to December in 2005 and the myocardial enzymes,and routine serum biochemical test and APACHEⅡscore were detected simultaneously.All the patients were classified to three groups according to the APACHEⅡscore (mild group,APACHEⅡ25) and two groups (survive group and death group) according to the prognosis.All the patients were followed up till recovery/discharge or death. Covariance,Wilcoxon and x~2 were used for the statistical analysis.Results The myocardial enzymes rose when the disease deteriorated and the APACHEⅡscore went up.AST,LDH,CK,CK-Mb,Mb were significantly different in the three groups according to the APACHEⅡscore (P