The present work was conducted to study the biological effect of different ratios of Doum and Psyllium husks seed as a source of dietary fiber on rats suffering from increase serum cholesterol. The results indicated that, samples of Doum and Psyllium husks seed contain high levels of carbohydrate being 94.94% and 89.85%, respectively. The crude fibers of these plants ranged between 6.7% in Psyllium and 13.62 % in Doum. The total dietary fibers (TDF) of the studied samples were significantly different and varied between 80.9% in Psyllium husks seed and 39% in Doum. As regard to the three dietary fiber fractions results indicated that the highest ratio of hemicelluloses was in Psyllium husks seed while, celluloses and lignin were recorded adverse direction. Two main experimental groups of rats were used. Group 1 (n=12 rats) used as a negative control group fed on basal diet. The other group (n = 60 rats) fed one week on diet containing 1% cholesterol + 0.2% cholic acid to induce high serum cholesterol, then this group was divided into five subgroups (12 rats each). The first subgroup fed on diet containing 1% cholesterol + 0.2% cholic acid (cholesterol diet), as a control positive group. Subgroups (2, 3, 4 and 5) fed on cholesterol diets containing 10 and 20% doum and Psyllium husks seed powder, respectively. The results indicated that, animals fed on diets containing Psyllium husks seed powder at levels of 10 and 20% produced larger fecal weight then those fed on diets containing the Doum powder at the same both ratios. Also, Psyllium husks seed powder groups recorded reduce in body weight gain and serum lipid profile (total lipid,  cholesterol, triglycerides, LDL-c, VLDL-c) as compared with control negative group, followed Doum powder group. Description of  histopathological alterations induced in colon, Aorta ,and heart of rats fed different rich-sources of dietary fibers of Doum and Psyllium husks seed showed the protective role of dietary fibers to prevent infection of high serum cholesterol.