Abstract: In recent years，mesoporous silica nanoparticles（MSNs）， by virtue of its unique physical and chemical properties，has won more and more attention as a novel drug delivery systems （DDSs） used in the biomedical field. Compared to traditional nano drug carriers such as liposomes，polymer nanoparticles. MSNs have a distinct advantage：to be effective in loading various drugs；the high drug loading capacity of MSNs making overcome tumor multidrug resistantce （MDR） becomes possible. More important fact is that there is a large number of silanol groups in the surface of mesoporous materials which may be used as the basis of multifunctional nanocomposites that makes tumors theranostics becomes possible. The application of MSNs in cancer therapy and diagnosis has been reviewed in this paper.

Key words: Silicon dioxide, Neoplasms, Drug resistance, neoplasm, Therapy, Diagnosis