Aim To study the relationship between the expression status of apolipoprotein E gene and children health,developed a new method for the quantification of apolipoprotein E mRNA in human monocyte-derived macrophages. Methods 10 mL venous blood was obtained from 26 health children.The mononuclear cells were isolated.Total RNA from the monocytes was extracted.Apolipoprotein E gene express were determined by reverse transcription-polymerase chain reaction. After synthesis of the internal apolipoprotein E DNA standard,we amplified internal standard DNA and cDNA of samples studied. Quantification of apolipoprotein E gene express was calculated. Results Apolipoprotein E mRNA was 0.37±0.15 mol/mol GAPDH mRNA in health children. Conclusions The competitive reverse transcription- polymerase chain reaction was a rapid,simple,sensitive method to study expression of apolipoprotein E gene. This method might be a valuable tool to assess apolipoprotein E gene expression in human disease.