Orthomorphic permutations have important applications in the design of block ciphers. A practical algorithm is derived to generate all orthomorphic permutations over F(superscript m subscript 2), and it is verified that the number of all orthomorphic permutations over F(superscript 4 subscript 2) is 244, 744, 192. With the theory of finite fields, a brief method is derived to generate a permutation polynomial corresponding to every permutation over F(superscript m subscript 2), and all orthomorphic permutation polynomials over F(superscript 4 subscript 2) are analyzed.