2 In order to study the effect of turmeric rhizome powder (TU) and enzyme in some blood parameters of laying hens, an in vivo study was conducted. In a 5 * 2 completely randomized block design with factorial arrangement, 5 levels of TU (0.0, 0.05, 0.10, 0.15, and 0.20 %) and 2 levels of enzyme (0.0, and 0.05%) with 4 blocks (replicate) , 480, 100-week old laying hens for 4 weeks fed wheat-soybean meal based diets. Some serum blood parameters of laying hens including hematocrit value, triglyceride, total cholesterol, HDL and LDL-cholesterol were recorded at 104 weeks of age. Increasing dietary levels of TU with or without a dietary enzyme significantly decreased serum triglyceride, total cholesterol and LDL-cholesterol (P<0.05). TU without enzyme significantly increased HDL-cholesterol. It was concluded that dietary supplementation of T U improves some of good indices of serum blood components in laying hens and might be used as a n ingredient in laying hen diets for manipulating egg composition.