This paper studies the seismic capability of the autoclaved fly ash bricks masonry structure.By using a nonlinear time-history analysis method,a great number of the nonlinear seismic response analyses of two typical masonry structures with the autoclaved fly ash bricks are performed respectively.It studies the seismic capability on the seismic fortification "three level" cases.The analysis results show that a 7-or a 6-storey building of the autoclaved fly ash bricks are building in seismic fortification intensity of 7 degrees and 8 degrees regions,it can meet three level requirements of aseismatic fortify;The seismic capability of this kind of building can improve once.