OBJECTIVE： To investigate the effect and mechanism of Allii macrostemonis bulbus on blood lipid levels in hyperlipidemia model rats， and to provide reference for clinical use of Allii macrostemonis bulbus to reduce blood lipid. METHODS： A total of 10 normal rats were included in normal control group and given common diet. Other 50 rats were given hyperlipid diet to induce hyperlipidemia rat model. 40 model rats were randomly divided into model group （hyperlipid diet）， Allii macrostemonis bulbus low-dose， medium-dose and high-dose groups （0.83， 1.67， 2.50 g/kg， fed by hyperlipid diet which containing 10％Allii macrostemonis bulbus 8.3， 16.7， 25.0 g/kg， fill with hyperlipid feed in patients with insufficient food intake）. After fed for 45 d， the contents of TC， TG， LDL-C and HDL-C in serum of rats were detected. Liver， spleen， renal and cardiac indexes of rats were calculated. mRNA expression of low density lipoprotein receptor （LDLR） and liver X-receptor α （LXRα）were detected in liver tissue of rats. RESULTS： Compared with normal control group， the contents of TC and LDL-C in serum and liver index of rats were increased significantly in model group， while the content of HDL-C in serum and mRNA expressions of LDLR and LXRα in liver tissue were decreased significantly， with statistical significance （P＜0.01）. Compared with model group， the contents of TC and LDL-C in serum were decreased significantly in Allii macrostemonis bulbus groups， while the content of HDL-C was increased significantly. mRNA expressions of LDLR and LXRα in liver tissue were increased significantly in Allii macrostemonis bulbus medium-dose and high-dose groups， while liver and spleen indexes were decreased significantly， with statistical significance （P＜0.05 or P＜0.01）. CONCLUSIONS： Allii macrostemonis bulbus shows good blood-lipid lowering effect， the mechanism of which may be associated with up-regulating mRNA expressions of LDLR and LXRα in liver tissue.