Recently, it has become easy to obtain medication without regular hospital visits as out-patients or previous hospitalization. This is mainly due to the development of the drug delivery system (DDS). However, to cope with the aging society in Japan, further investigation is necessary to establish a highly effective DDS. Against this background, an important project is to develop new materials which constitute such medication. Mesoporous silicas, which possess uniform pores to incorporate medicines are noted as new materials in a wide range of research fields. In this context, I have studied development of a photo-triggered drug release system with mesoporous silica through photo-decarboxylation.