Abstract: Objective To explore the influence of the examstress on blood serum biochemistry and mimunity parame ters as well as their correlations with the pheno type of HLA-DQB1 in healthy volunteers.Methods Twenty seven students of middle school,who would take the exam a month later,and 24 students,who began to study aftervacation,were selected as observation group and control group respectively.The blood serumbio chemistry,immunity parameters included albumin (ALB),total prote in,total bilirub in,direct bilirubin(DBIL),urea,creatinine,uric acid,glucose(Glu),a lanine aminotransferase,a sparta team inotransferase(AST),alka line phosphatase(ALP),glutamyl transpeptidase,potassium(K),so dium,chlorinum,calcium(Ca),chole sterol(Chol),trigly eride,high density lipoprote in,low density lipoprote in and IgG,IgM,IgA,C3,C4,were measured with automatic analyzer.HLA-DQB1 a lleles were individually amplified by PCR.Results Exam stress significantly increased the contents of Alb(50.1±1.6 vs 47.5±2.0 g/L),Glu(4.8±0.3 vs 4.5±0.5 mmol/L),ALP(94.6±26.0 vs 70.9±18.4 IU/L),Ca(2.4±0.1 vs 2.3±0.1 mm ol/L),K(4.2±0.3 vs 3.9±0.3 mmol/L)and C3(1122.5±169.2 vs 1015.1±202.4 mg/L)while decreased DBIL(3.3±1.4 vs 4.2±1.6 mol/L),AST(16.3±3.7 vs 20.3±8.7 IU/L)and Chol(3.6±0.5 vs 3.9±0.7 mmol/L)in blood serum(P<0.05).There was no significant difference in measured values between people with and without each allele at HAl-DQB1.Conclusion Exam stress could induce significant blood serum biochemistry,mimunity changes and these indexes may be biom arkers of social psychology stress.