Aim To investigate the relationship of nitric oxide (NO) and macrophage-mediated oxidation of low density lipoprotein (LDL). Methods Mice were given peritoneal injection polysaccharide krestin (PSK) (control mice were given injection physiological saline), peritoneal macrophages were collected for incubation and stimulated with LDL, interferon-γ (IFN-γ), lipopolysaccharide (LPS) and L-arginine (L-Arg). Contents of change of NO and hydroperoxides were measured. Results There is a quantity effect significance between NO and oxidation of LDL. It showed a negative correlation when the contents of NO within a certain range (approximately ≤50 μmol/L) and the contents of hydroperoxide (LOOH) decreased with that of NO increased, it meant to inhibit LDL oxidated. When the contents of NO were excessive (approximately ≥90 μmol/L) , the contents of LOOH increased with that of NO increased, it's a positive correlation and meant to promote LDL oxidated. Conclusions The results indicated there is a double effects of NO on oxidation of LDL, to inhibit or promote oxidation of LDL decided on the contents of NO.