Aim To study the effect of G4A polymorphism on serum lipid level of Han population in Hunan province. Methods G4A Polymorphisms of the scavenger receptor class B type I (SR-BI) gene were detected by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) in atherosclerotic cerebral infarction (ACI) patients, cerebral hemorrhage (CH) patients and healthy controls. Results The serum level of high density lipoprotein cholesterol (HDLC) in SR-BI G4A GA+AA genotype subgroup was markedly higher than that in GG genotype subgroup of the same group in ACI group (P<0.05), and it was the same with CH group. The serum level of low density lipoprotein cholesterol (LDLC) in SR-BI G4A GA+AA genotype subgroup was evidently lower than that in GG genotype subgroup of the same group in ACI group (P<0.05), and it was the same with CH group. The serum level of HDLC in SR-BI G4A GA+AA genotype subgroup was obviously higher than that in GG genotype subgroup of the same group in control group (P<0.05). The serum levels of LDLC and total cholesterol (TC) in SR-BI G4A GA+AA genotype subgroup was significantly higher than those in GG genotype subgroup of the same group in control group (P<0.05). The serum level of HDLC in male ACI group and GA+AA genotype subgroup of CH group was markedly higher while LDLC was markedly lower than that in GG genotype subgroup of the same group. There was no significant difference of body mass indexes and serum level in different genotype subgroups of female ACI group and CH group. Conclusions A allele of SR-BI G4A is possibly associated with the metabolism of HDL and LDL.