Based on analysis of the effects of compression to image feature extraction, a quantitive method is proposed to evaluate the effects of compression to image feature extraction. The feature of image is extracted, and change detection method is used to statist the effect of compression. The compression test used JPEG2000 to SPOT5 image showed that the proposed method can obtain the coherenceedge curve, and has strong ability to remove noise; line feature extraction results are applicable to feature change comparison; the method can also reflect the different image information loss of multiple compressed ratio, the higher of line feature change rate, and the more of compression image information loss.