Objective To systematically introduce the classification and properties of bioadhesive materials,the mechanisms of bioadhesion,the factors that influence the bioadhesive behavior,the evaluation methods for bioadhesion,the application of bioadhesive materials in pharmaceutical dosage forms and the problems existed accordingly. Methods Consult the recent journals and books,and make integration. Results The bioadhesive drug delivery system is the interest of many pharmaceutical researchers. However,the number of bioadhesive materials with satisfied quality is far less enough,the mechanisms of bioadhesion are still not quite clear,and the methods for bioadhesion evaluation leave much room to improve. Conclusions Bioadhesive materials shall have a very good prospect in the drug delivery system.