Abstract: ObjectiveTo learn about the gene polymorphism at LDL receptor-AvaⅡ locus and its relations with serm lipids profile in children of Han Nationality.MethodsIn 308 children the LDLR-AvaⅡ polymorphism and serum lipids profile were detected.ResultsIn children the frequency of heterozygote was 35.7% and allele(+)was 17.9%,that similar to internal reports(14.7%),but much less than caucasian(43%).There were no significant differnece among three genoty pes for serum lipids profile in male and female children.And also the genotype distribution of LDLR-AvaⅡ locus in hyper cholesterolemia group was not significantly different from control group.Several factors may be associated with the negative results:(1)The genetic variation was multiple,polynor mal and different among various ethnic population.(2)One gene locus always was "minor gene".(3)The period of environmental effects was too short for susceptible children to have the serum lipids profile changes sig nificantly.(4)Confounding factors.ConclusionThe study couldn't draw the conclusion that the polymorphism at LDLR-AvaⅡ locus was associated with serum lipids profile in children.