Abstract: Recently, plenty of researches have been done on the tumor targeting nano-medicines. As the study on tumor progression, invasion and metastasis deepens, tumor micro-environment responsive nano-preparations become an issue of increasing concern. Enzymes represented by matrix metalloproteinase(MMP) are highly expressed within the tumor micro-environment. Therefore, its substance can be designed for drug delivery and imaging. In this review, nano-delivery system responding to MMP and other highly expressed enzymes are generally introduced.