Bayon temple, Angkor, consists of dry-masonry structures made of sandstone. Strong wind in the rainy season is suspected as one of the causes for its progressive deterioration. Since 2003, micro-tremor has been measured at most of the tower-type structures and the continuum-equivalent elastic modulus was found to be 1/9 to 1/27 of that of the sandstone specimen in laboratory tests. In 2006, micro-tremor was measured at libraries in Bayon temple and the similar reduced equivalent modulus was also obtained for these frame-like sandstone-dry-masonry structures. This extremely low elastic modulus implies the inadequacy of continuum modeling for bearing capacity of dry-masonry structures. Then the Discontinuous Deformation Analysis was applied to safety evaluation of the library against wind load. It was an illustrative example; however, the evaluated safety margin for the wind velocity of 40 m/s is about two.