Objective To detect the salivary levels of IgA,alpha-amylase and acetylcholinesterase (AChE) and saliva flow rates of IgA in normal controls versus Parkinson disease (PD) patients,and to analyze the correlation of these salivary biochemical indexes with disease duration,H&Y rating scale,SCOPA-AUT score,sialorrhea score,dry mouth score and the use of levodopa.Methods Thirty-eight PD patients including twenty-two patients treated with levodopa,and twenty-one normal controls were selected in our study.About 3 ml saliva was collected from each subject.Salivary IgA was detected by immunoturbidimetry.Alpha-amylase and AChE were tested by enzymatic colorimetry.The protein concentration was analyzed by BCA kit to normalize ACHE.The salivary flow rate and IgA flow rate were also calculated.Results Salivary flow rate (ml/min) was (0.39±0.22) in normal controls,and (0.35±0.28) in PD groups;the level of IgA (mg/L) was (148.3±86.1) in normal controls,and (183.7±126.3) in PD groups;IgA flow rate (μg/min) was (47.8±25.9) in normal controls,and (46.9±27.1) in PD groups;the level of alpha-amylase (U/L) was (1.63 ± 1.21) × 105 in normal control,and (1.35 ± 9.87) × 105 U/L in PD group;and the level of AChE (U/mg) was (0.12±0.08) in normal controls,and (0.09±0.05) in PD group.No statistically significant differences in above indexes were found between PD group and controls.There were negative correlations between salivary flow rate and dry mouth score (r =-0.445,P =0.005) and between alpha-amylase concentration and sialorrhea score (r=-0.327,P=0.045).The positive associations were found between IgA concentration and the SCOPA-AUT score (r =0.438,P =0.006),and between IgA flow rate and sialorrhea score (r =0.411,P =0.01).Conclusions Salivary flow rate and level of alpha-amylases tend to be decreased in PD patients,while IgA concentration has an upward tendency.Salivary alpha-amylases concentration and IgA flow rate are correlated with the symptom of sialorrhea,while IgA concentration correlates with the degree of autonomic symptoms.These measurements can be used as indexes for evaluating the lesions of the autonomic nervous system.