Abstract: By means of the rain attenuation time series synthesizer presented by ONERA-CNES and the measured rainfall attenuation data in Beijing and Hainan area, the rain attenuation time series are simulated at Ka-band (30/20GHz). The power spectral densities of the rain attenuation time series are estimated by FFT and Kaiser Window function, and compared with the literature results obtained by test rainfall data. The spectral slopes are in agreement with the -20dB/decade in literature. The rainfall time probabilities of annual average are analyzed statistically by the rain attenuation time series. The results agree with the results on the basis of measured rainfall data and the one predicted by ITU-R model. It is shown that this method can be effectively applied to the simulation and analysis of the dynamic rain attenuation time series at typical regions in China. This research establishes a base for the development of the rain Fade Mitigation Techniques in communication and radar systems at Ka and above Ka band.