The　bimodal　molecular　sieves　with　the　structure　of　nano　ZSM-5　were　synthesized　by　using　degradation　liquid　with　the　primary/secondary　structure,　which　was　prepared　through　degradating　ZSM-5,　as　silica　source,　and　cetyltrimethyl-ammonium　bromide　(CTAB)　as　template　respectively,　and　charactered　by　XRD,　TEM,　SEM.　The　results　showed　that　the　bimodal　mesoporous　composite　molecular　sieves　were　of　high　hydrothermal　thermal　stability　and　the　spherical　particles　with　the　size　of　around　100　nm.　In　addition,　the　size　of　nano　ZSM-5　is　below　20　nm.