Mesoporous silica nanoparticles as drug carrier have become the new hot point in the field of biomedical application in recent years. This review focuses on the more recent developments and achievements on experimental design aspect of mesoporous silica nanoparticles with cancer diagnosis and therapy. The key advances of functionalization strategies of mesoporous silica nanoparticles with controlled release, tumor targeting and overcoming multidrug resistance are discussed in particular. Mesoporous silica nanoparticles as unique delivery systems have the potential to provide significantly a sound platform for cancer theranostic application.