This article will introduce K-modal BL-algebra and investigate some properties of this new algebra. Consequently, K-modal filters and -tautology filters as filters of K-modal BL-algebras will be dealt with. We will prove that the class of all K-modal BL-algebras is a variety of algebra. Our final goal in this paper is to prove that a K-modal BL-algebra is a sub-algebra of direct product of a system of linearly ordered K-modal BL-algebras under special conditions.