The main target of this study was evaluating the effect of two concentration of dry and germinated oat consumption 15% and 30% for 6 weeks on hypercholesterolemic rats. Thirty six male albino rats were used in this study and divided into six groups. First group fed on basal diet and used as a (negative control group). Second group fed on hypercholesterolemic diet (HCD) (diet containing 1% cholesterol,16% saturated fat and 0.25% colic acid) and used as a positive control. Groups (3 and 4) rats fed on HCD containing 15 and 30% whole dry oat. Groups (5 and 6) rats fed on HCD containing 15% and 30% germinated oat. The results demonstrated that HCD caused a significantly increase in TC, TG, low density lipoprotein cholesterol, very low density lipoprotein cholesterol, Atherogenic index (AI), LDL/HDL ratio, AST, ALT and kidney function, Furthermore, it caused a significantly decrease in HDL, HTR, GSH, CAT, SOD and GPx .The rats received dry oat with high concentration (30%) was the most effective to reduction of TC, TG, LDL-C and VLDL-C than dry 15% and germinated 15%. While, germinated oat 30% revealed non- significant effect on TC and LDL-C levels, although it has more effective to raise antioxidant enzymes a activity. All treatments revealed a significantly decrement of AI, AST, creatinine, uric acid and urea. Conclusion: addition of whole dry and germinated oat to HCD for 6 weeks has potential effects to reduced serum cholesterol levels, LDL-C and VLDL-C.