This experiment is carried out to study influence of vitamin $B_6$ on serum lipids of rat fed with oxidized oil by heat. The experimental animals use 35 male Sprague-Dawley rats weighing 100 ${pm}$ 2g. They are divided into 5 groups and fed to experimental diets which are added to 10%, 15%, 20% oxidized oil by heat in addition to 0.01%, 0.04%, 0.06% vitamin $B_6$. Oxidized oil by heat is prepared from the soybean oil by heating at $180^{circ}C$ for 50 hours. After feeding for 4 weeks, lipid concentrations of sera are as follows; 1. Body weights are higher in experimental diet groups than control diet group. 2. Liver weights are higher in experimental diet groups than control diet group, but spleen weights are lower in experimental diet groups than control diet group. 3. The contents of serum total cholesterol, free cholesterol, HDL-cholesterol are lower in experimental diet groups than control diet group. 4. The contents of serum triglyceride are significantly higher in experimental diet groups than control diet group. 5. The contents of serum phospholipid are lower in experimental diet groups than control diet group.