Tenderization of beef by the addition of barks(Morus alba Linne) and its sensory properties were observed by shearing test, cooking loss, pH, protein content and sensory evaluation. Shear force was decreased as the addition level of barks (Morus alba Linne) increased. Tenderization effect of beef was increased 8,8% at the addition level of 2.5%, 25% at 5.0%, 4.7% at 7.5%, 58% at 10% barks(Morus alba Linne). Cooking loss was observed 44.50% at the no addition, 45.3% at 2.5%, 45.8% at 5.0%, 47.5% at 7.5%, 50.0% at 10% addition level of barks (Morus alba Linne). As the addition level of barks(Morus alba Linne) increased pH of cooked beef decreased to the range of 5.6 to 5.46. As the addition level of barks (Morus alba Linne) increaed protein content of beef decreased whereas protein content of cooled liquor increased. The addition of barks(Morus alba Linne) improved the sensory quality of cooked beef. Especially, tenderness scored the highest value in 10% added beef and other quality factors color, flavor, juiciness and overall quality were evaluated significantly high in 5% added beef. Therefore 5% addition level of barks(Morus alba Linne) for cooking beef was suggested as the desirable level of addition.