The reduction of CO2 emission has been a worldwide mission to resolve global warming predicament. Mesoporous silsesquioxanes, which stabilized by organobridges and has high content aminon absorption site, can serve as a potential CO2 adsorbent. Synthesis of such material is done by hydrolysis and polycondensation of trialkoxysilane. The fastest gelation was observed at reaction in the absence of acids or bases. However, addition of surfactant to the reaction mixture catalyzed formation of silsesquioxanes in acidic media. Obtained materials are strongly hydrophilic and possess a high thermostability. Study of particle size distributions showed that in all cases it was bimodal. The largest particles formed in basic media. Mesoporous silsesquioxanes were obtained from bridged alkyltrimethoxysilanes in the presence of surfactants.