Linum Usitatissimum (LU) has a lipid-lowering action in both normal and diabetic animals. Because OS leaves are rich in oil, the present study was conducted to explain the anti-hyperlipidemic and organ-protective effect of LU fixed oil in rats fed with a high fat (HF) diet. LU fixed oil was extracted by hexane and the fatty acids composition identified by GC-MS. Four groups of male Wister rats included a normal control group, a high fat fed-diet (HF) group, a HF group treated with LU fixed oil, and a HF group treated with a reference drug Atorvastatin. The results show that LU fixed oil contains five kinds of fatty acids, of which alpha-linolenic acid was the major fatty acid. LU fixed oil depressed high serum levels of total cholesterol, triglyceride, LDL-C, and AI, whereas no significant effect on HDL-C was observed. LU fixed oil also suppressed high levels of liver cholesterol and triglyceride with no significant effect on both lipids in feces. In addition, LU fixed oil normalized the high serum levels of LDH and CK-MB but no significant effect on high serum levels of ALT, AST, and ALP was obtained. We conclude that treatment with LU fixed oil during the last three weeks of HF diet feeding decreased the high serum lipid profile and expressed anti artherogenic and cardio protective actions against hyperlipidemia. The anti-hyperlipidemic action of OS fixed oil was mainly resulted from the suppression of liver lipid synthesis. Linolenic acid and linoleic acid contained in LU fixed oil were possibly responsible for both lipid-lowering and cardiac protective action against hyperlipidemia.