The indexing of the images from huge remote sensing databases is a key issue for the space agencies. A particularity of remote sensing image databases is that the images are with different but known spatial resolutions. In this paper, the joint indexing of remote sensing images with different spatial resolutions are investigated. The main contribution of this paper consists in proposing the approaches for comparing the features extracted from the images with different spatial resolutions, which are usually not comparable. The experimental results obtained on satellite images taken by SPOT5 and SPOT have validated the proposed comparing approaches.