An experiment was conducted to investigate the effect of adding sodium bicarbonate to the ration on milk yield and some of its components and blood parameters for local Friesian dairy cows. In this experiment 3 non pregnant cows were used at same live weights, third production season and during first month of calving, they were divided into three groups and fed individually on three rations during three periods (28 days / period).Sodium bicarbonate was added daily to the basal ration at a level of 100 and 200 g/cow /day for 2nd and 3rd groups, respectively, while the 1st group was considered as a control ration. The results indicated that daily and adjusted milk yield, fat%, quantity of fat, protein and lactose (gm/day) were increased significantly (P≤0.05) in 3rd group as compared to those in the 1st group. While the results indicated that blood pH,hemoglobin ,red & white blood cell count, packed cell volume, hemoglobin concentration, total protein, albumin, globulin, cholesterol ,triglyceride, urea, glucose, ALT, AST, ALP enzymes, calcium, sodium, phosphors, magnesium and potassium were not significantly affected by supplementation of sodium bicarbonate to 2nd and 3rd ration. There were no significant effects for the interaction between treatment × period on all the studied traits. It is concluded that using 200 g.of sodium bicarbonate per cow per day had improved milk production ,fat percentage of milk and had no side effect on all blood parameters.