The present invention provides an antibody that specifically binds to human aggrecanase, and inhibits enzymatic activity of the human aggrecanase. In one embodiment, aggrecanase is ADAMTS4. In one embodiment, the antibody recognizes a particular epitope in human ADAMTS4, and inhibits not only aggrecanase activity of human ADAMTS4 but also aggrecanase activity of human ADAMTS5. In addition, the present invention also provides use of said antibody in the prophylaxis or treatment of the progression of arthritis.