Abstract. In this paper we characterize multi-Jensen functions f : V n → W , where n is a positive integer, V, W are commutative groups and V is uniquely divisible by 2. Moreover, under the assumption that f : R → R is Borel measurable, we obtain representation of f (respectively, f, g, h : R → R) such that the Jensen difference(respectively, the Pexider differencetakes values in a countable subgroup of R.