Aim To study nitric oxide (NO) variances after vascular endothial cell were impacted by low density lipoprotein (LDL) and high density lipoprotein (HDL). Methods Concentrations of NO in the cultured medium were detected in 2 h, 6 h, 12 h and 24 h after the addition of LDL, HDL and both of them respectively in the guinea pig vasular endothial cell. Results LDL could obviously decrease the NO synthesized by vasular endothial cell with dose depentent (P<0.01)and HDL could arise it (P<0.01), LDL mixed with three levels of HDL expressed the same effection as LDL alone (P>0.05). There was no difference in four time's group (P>0.05). Conclusions NO synthesized by vasular endothial cell will be restrainted by LDL and arisen by HDL but couldn't antagonist the former's.