CSKH-02.2017 - (Abstract) In this paper, the iterative scheme, namely the -scheme, is proposed constructing block ciphers. Then, the pseudorandomness and superpseudorandomness of this scheme are evaluated by using the Patarin’s H-coefficient technique. In particular, the pseudorandomness of -scheme is achieved in the case that the number of round is at least 3, and -scheme is superpseudorandomness in the case that the number of round is greater than or equal 5. However, we have not yet evaluated superpseudorandomness of this scheme when the round is 4.