We present in this paper the alternating minimization method on CAT(0) spaces for solving unconstraints convex optimization problems. Under the assumption that the function being minimize is convex, we prove that the sequence generated by our algorithm converges to a minimize point. The results presented in this paper are the first ones of this type that have been given for theses spaces and alternating type methods. Moreover, the method proposed in this paper is attractive for solving certain range of problems.