To explore the relationship between polymorphism of alpha 1-antichymotrypsin(AACT) and apolipoprotein E(ApoE) genes and the risk of Parkinson's disease(PD) in Shanghai Hans.Polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) were used to study the distribution of AACT and ApoE gene polymorphism in 64 PD cases and 101 healthy elderly persons as controls. Association analysis was performed using odds ratio (OR) and chi 2 test.No difference in distribution of AACT A/T allele polymorphism was found between PD cases and healthy controls(chi 2 = 0.83 P = 0.363 > 0.05), but AACT-AA genotype was associated with PD(OR = 2.68, chi 2 = 4.31 P = 0.038 0.05; genotype: chi 2 = 9.25 P = 0.099 > 0.05). The AACT-AT genotype frequency in PD patients was significantly lower than that in the controls without ApoE epsilon 4 allele(OR = 0.47, chi 2 = 4.10 P = 0.043 < 0.05). In AACT-AT genotype the ApoE epsilon 4 allele was associated with PD(OR = 3.26, chi 2 = 5.53 P = 0.019 < 0.05).The AACT-AA genotype and AACT-AT genotype with ApoE epsilon 4 might be susceptible factors for PD in Shanghai Hans.