In this paper we investigate a categorical aspect of n-trivial extension of a ring by a family of modules.Namely,we introduce the right (resp.,left) n-trivial extension of a category by a family of endofunctors.Among other results,projective,injective and fiat objects of this category are characterized,and two applications are presented at the end of this paper.We characterize when an n-trivial extension ring is k-perfect and establish a result on the self-injective dimension of an n-trivial extension ring.