To investigate the disorder of lipid metabolism and explore the possible mechanism of increasing risk of atherosclerosis(AS) in simple childhood obesity, serum lipids and apolipoprotein were examined. 49 obese children were selected and another 49 non-obese children were selected as control. Their serum lipids (TG, TC, VLDL-ch, HDL-ch and LDL-ch) and apolipoprotein(apoA1 and apoB100) were measured. The results showed TG, VLDL-ch, apoB100, artherosclerosis index (AI) and LDL-ch/HDL-ch ratio in childhood obesity were significantly higher than that in normal children (P < 0.05), while HDL-ch, apoA1, HDL-ch/TC, apoA1/apoB100 ratio in obese children were obviously lower than that in normal ones(P < 0.05). The results suggested that metabolic disorder of lipid and apolipoprotein took place in obese children. The disorder which may increase the risk of AS should be paid great attention.