The morphological and chemical characteristics of leaves and fruits were observed in the three mulberry varieties, including Daeryugppong(Morus Lhou(Ser.) koidz), Kugsang 20(Morus Lhou(Ser.) koidz) and Cataneo(Morus alba L.). The leaf development in spring was earliest in Cataneo and latest in Kugsang. Content of total nitrogen and Mg in leaf was the highest in Cataneo while that of P2O5, K and Ca in Daeryukppong. Flowers started to bloom from May 8 and in full bloom around May 15. Mature fruits began to set from June 10 to 15 and lasted by July 10 in Cataneo. Average fruit weight was heaviest in Kugsang 20(3.52 g/fruit), while lowest in Daeryukppong(1.61 g/fruit). In fruits, glucose and fructose were the major sugars. Citric acid was the most abundant organic acid in three varieties with its average content from 0.8 to 0.14%. The major pigment in fruit was anthocyanin and its content varied among varieties. The stability of anthocyanin was evaluated under various pH, temperature, and sugar concentrations. Rutin was the major flavonol glycoside present in fruits and its content varied from 0.92 to 3.36 mg/gDW. Other flavonol glycosides such as isoquercitrin and quercitrin were also detected in fruit.