Objectives : In order to distinguish morphological characteristics, because the inside portion of the root bark of Scutellariae Radix decomposes as time goes by, 2nd, 3rd, and 5th year Scutellariae Radix were sampled and compared according to their external, internal, and flour states through optical microscope. Methods : The slice of the tested material made by paraffin section technique was colored with Safranine Malachite Green contrast methods, and the flour of it was mounted by the liquid made by the same ratio of each of glycerin, acetic acid, and water, and then observed and photographed by olymphus-BHT. Results : 1. The inside of 2nd year Scutellariae Radix was rich and golden, the transverse section of Scutellariae Radix that was 3rd years of age was golden, but there were many Scutellariae Radix whose center portion turned redish brown, and the center portion of 5th year Scutellariae Radix had been decomposed or empty. 2. 2nd year Scutellariae Radix had the most starch grain, 5th year Scutellariae Radix had the least, and the middle portion of xylem that was 5 years of age had a cell ring that was corkish, but 2nd and 3rd year Scutellariae Radix did not have it. 3. In the flour state, 2nd, 3rd, and 5th year Scutellariae Radix did not have any difference, but the amount of starch grain was the most in 2nd year Scutellariae Radix and the least in 5th year Scutellariae Radix.