Some strong convergence theorems of explicit iteration scheme for asymptotically nonexpansive semi-groups in Banach spaces are established. The results presented in the paper not only extend and improve the corresponding results of Aleyner-Reich [1], Shioji-Takahashi [8], Suzuki [9] and Xu [12], but also give a partially a±rmative answer to the open questions raised by Suzuki [9] and Xu [12].