It　is　essential　to　control　tobacco　specific　N-nitrosamines　(TSNAs)　pollution　for　the　protection　of　public　health,　which　were　identified　as　the　most　abundant　carcinogens　in　tobacco　and　tobacco　smoke.　Herein,　we　provide　microporous　TiO2　mesocrystals　as　a　new　material　for　the　remove　of　TSNAs　with　high　degradation　efficiency.　The　anatase　TiO2　mesocrystals　with　tunable　microporous　structure　were　synthesized　by　a　facile　method　under　the　acid　solution.　The　TiO2　mesocrystals　were　firstly　used　to　the　remove　of　TSNAs　through　photocatalytic　degradation.　It＇s　exciting　that　TSNAs　of　tobacco　extraction　solution　can　be　almost　entirely　reduced　(up　to　97%)　by　anatase　TiO2　mesocrystals　after　30　mins　through　photocatalytic　degradation.　Moreover,　it＇s　found　that　the　microporous　size　of　mesocrystals　play　a　key　role　on　the　degradation　capability.　The　TiO2　mesocrystals　with　microporous　size　comparable　to　the　size　of　TSNAs　molecule　exhibit　the　best　degradation　performance.　This　finding　offers　a　robust　microporous　material　and　efficient　method　for　removing　the　carcinogen　like　TSNAs　as　well　as　other　pollutants　in　environment.　©　2018　Wiley-VCH　Verlag　GmbH　&　Co.　KGaA,　Weinheim