Fractal dimension with various algorithms has increasing applications in characterizing both linear and areal features. In this study, the variabilities of sea surface topography derived from TOPEX/POSEIDON are studied. The variogram method is applied to compute fractal dimensions for each scene. Cumulatively, 29 scenes taken from 1992, 111 scenes taken from 1993, 110 scenes from 1994, 98 scenes taken from 1995 and 38 scenes taken from 1996 are analyzed. The spatial resolution of each scene is two degrees along both longitudinal and latitudinal directions. The annual averages of fractal dimensions are 2.528, 2.527, 2.523, 2.523 and 2.524 for 1992, 1993, 1994, 1995 and 1996, respectively.