Let A and B be two prime C-algebras. In this paper, we investigate the additivity of map from A onto B that are bijective unital and satis es (AP + PA) = (A)(P) + (P)(A); for all A 2 A and P 2 fP1; IA P1g where P1 is a nontrivial projection in A and 2 f1; +1g. Then, is -additive.