Quick and accurate evaluation of the building damages after earthquake in urban area is a critical issue for timely assessing the disaster situation and effectively carrying out rescue mission. Very High Resolution （VHR） optical image is usually a direct way to visually monitor natural disaster occurrence. However

under some serious situations

such as bad weather or difficult geographic conditions

the post-event VHR optical image is not always available over large areas. All day and all weather space-borne Synthetic Aperture Radar （SAR） in operation can provide the reliable and high quality images over a large area. Of course

the relationship between optical image and SAR image is not simply a one-to-one visual correspondence. Microwave scattering and penetration through terrain media

and image speckles of SAR observation with a certain resolution are different from VHR optical imaging. How to make fusion of VHR optical and SAR images under different pre-event and post-event situations can provide a useful and operational approach to make timely and accurate evaluation of earthquake losses.