In this paper, we mainly parameterize $g$-frames in Hilbert space in terms of operators. Firstly, under the condition that there exists a $g$-orthonormal basis we establish the one to one correspondence between different kinds of $g$-frames with certain kinds of operators. Then we parameterize $g$-frames without the above restriction. Finally, we consider some special $g$-frames, and their operator parameterizations are established. We also obtain some interesting results on $g$-bases and $g$-dual frames of the transforms by applying the operator parameterizations of $g$-frames.