Rain attenuation is the dominant cause of leading up to the signal degradation in satellite links operation at Ka - band. Presently, most of rain compensation algorithms come from the aspect of the application of power and bandwidth and are based on the use of a fixed, large fade margin in combating the occasional deep fades. However, such use of a fixed margin, especially for a rainy region, results in an inefficient use of channel capacity. Therefore, based on the effective utilization of the channel capacity, the paper discusses the performance of satellite channel capacity in the Ka - band in the presence of rain attenuation, presents some useful results on the basis of analysis.