Abstract: In order to know the performance of algorithm for space-borne SAR raw data compression and choose proper compression scheme, evaluation of compression algorithm is indispensable. By defining some of evaluation parameters, this paper utilizes actual ground simulation raw data to evaluate Block adaptive Quantization (BAQ) algorithm on different data separation scheme and compression ratio respectively. Numerical experiments show that BAQ algorithm neither affects spatial resolution nor generates geometric distortion. It has only a little effect on radiometric resolution. The distortion of image main-lobe peak can't be corrected uniformly. At the same time, this evaluation method can be used in evaluation of other algorithms for SAR raw data compression.