Both hydrolysed guar gum and polydextrose have been used as a major fiber source in preparations of unctional drink products and other food products. In this study we determined the effects of these fibers on lipid metabolism of normal rats with two different dietary fat levels by using cellulose as the control. Serum total lipid triglyceride total cholesterol and HDL-colesterol were determined with proper enzymatic methods. Feed intake weight gain and feed efficiency ratio were also calcula-ted. Polydextrose-fed group showed lower serum triglyceride level than hydrolysed guar gum-fed group regardless of fat level used in this study without changing total lipid level in the serum. We also observed that polydextrose-fed group showed low serum cholesterol level nummerically high serum HDL-cholestrol level and more excretion of fecal neutral sterols when compare with those values of hydrolysed guar gum-fed group. The results indicate that polydextrose might have more beneficial roles in lipid metabolism when compare with hydrolysed guar gum.