Y.Imai and K. Iseki introduced two classes of abstract algebras:BCK-algebras and BCI-algebras([3,4]).It is known that the class of BCK-algebras is a proper subclaass of the class of BCI-algebras. In [1,2], Q.P.Hu and X. Li introduced a wide class of abstract: BCH-algebras. They have shown that the class of bci-algebras is a proper subclass of the class of bch-algebras.In 5
H.S.kim and Y.H.kim introduced the notion of a,be-algebra as a dualization of generation of abck:algebras. In this paper,we introduced the notion of derivation in a be-algebr, and considered the properties of derivation.Also,we characterized the fixed set fix(d)(x) and kerd by derivation. Moreover,we prove that if d is a derivation of BE-algebra,every filter F is a d- invariant.