Bimodal　mesopores　silicas　(designated　as　BMMs)　with　tailored　morphology　and　controlled　structure　have　been　synthesized　via　varying　additive　ammonia　amount　in　the　TEOS-CTAB-H2O　system　based　on　hydrolysis　condensation　behaviors　of　silicate　species　(TEOS)　and　coefficient　principles　of　cetyltrimethylammonium　bromide　template　(CTAB).　The　spherical　BMMs　with　an　average　diameter　of　25　-150　rim　were　prepared　in　a　relative　low　ammonia　concentration　solution,　while　the　rod-like　BMMs　with　an　average　size　of　2　pm　in　length　were　obtained　under　a　high　ammonia　concentration　aqueous　solution.　Meanwhile,　their　corresponding　morphologies　and　textural　properties　were　characterized　by　various　techniques,　such　as　X-ray　diffraction,　SEM,　TEM,　FT-IR,　TG,　and　N-2　sorption,　and　then,　the　related　cooperative　mechanism　including　sol　gel　chemistry　and　self-assembly　process　was　put　forward.　(C)　2013　Elsevier　B.V.　All　rights　reserved.