X‐ray time series data from the 4.8‐second binary pulsar Cen X‐3 observed with Ginga are analyzed. We study the fractal dimension of x‐ray intensity of the total 1.7∼37 keV energy band. The fractal dimensions of the temporal behavior on time scales ≥4.8 seconds are comparatively large. It implies that the source varies with small size perturbations compared with the scale of the system. The effect of noise on the fractal dimension is estimated briefly. It is mentioned that there exists a low dimensional motion with the time scale of 500 s. ©1994 American Institute of Physics.