Abstract: Traditional building damage detection using post-event synthetic aperture radar (SAR) imagery is usually performed based on street block area， few on imaging geometry structure (IGS). In this paper， the characteristics of individual damaged or undamaged buildings are firstly analyzed based on SAR IGS. Then a building damage analysis method based on SAR IGS is proposed by accumulating the SAR intensity in range direction in order to extract the layover and shadowing areas of undamaged buildings as well as the damaged areas of collapsed buildings. Next, we compute the texture features such as homogeneity， dissimilarity and entropy in these areas， and compare the composited texture features with undamaged and collapsed buildings. Finally, the post-earthquake airborne high resolution SAR data of Yushu M_S7.1 earthquake are collected and analyzed by using the above method. The results show that layover， shadow and double bounce are effective features of SAR IGS to identify whether a building is damaged or not， among which the texture features in layover and shadow-ing areas perform well. What is more， using SAR IGS can apparently improve the recognition ability of damage detection compared with traditional methods using statistical features. The SAR IGS is of great significance to study and application in detecting collapsed buildings from high resolution SAR imagery.