Abstract: In Z-pinch experiment, the one-dimensional temporal-spatial distribution of X-ray power is recorded by photographic films with nonlinear luminosity response. After processing by using a simulative characteristic function, the X-ray images are spatially integrated and then compared with X-ray waveforms obtained with X-ray Power Meter. The results show that the two kinds of waveforms are well coincident, which validates the capacity of the simulative characteristic function.