Sunflower oil and tallow were interesterified in different ratios (1:9, 2:8 and 4:6 w/w), at various degrees of temperature, for many periods of time. Using sodium methoxide (0.3% w/w) and sodium hydroxide: glycerol: water (1:2:3 w/w) as catalysts. Acid value, iodine value, peroxide value and melting point of interesterified and non- interesterified (control) blends were analysed. Solid fat content, trans fatty acids and fatty acid compositions of selected interesterified blends were determined. Iodine values of all blends with all conditions were more or less equal to iodine values of their control samples, while acid values of interesterified samples were decreased relative that of  control sample. Interesterified samples which obtained using sodium hydroxide: glycerol: water (1:2:3 w/w) gave preferable peroxide value more than that using sodium methoxide(0.3% w/w).Trans fatty acids of selected interesterified samples using sodium hydroxide: glycerol: water (1:2:3 w/w) were better than those selected interesterified samples using sodium methoxide (0.3% w/w).