Abstract
In this paper, by considering the notion of fuzzy hyperoperation, we define the concept of fuzzy hyper BCK(BCI)-algebras as a generalization of BCK(BCI)-algebras and study related properties. Moreover, we introduce the notions of fuzzy hyper BCI-ideal and weak (strong) fuzzy hyper BCI-ideal, and then examine the relations among them. Finally, we investigate the relation between fuzzy hyper BCI-algebras with fuzzy hypersemigroup, fuzzy hypergroup and hyper BCI-algebras.