Objective: Degenerative osteoarthritis of knee joint of many old men was very difficult to treat.Conservative treatment was less effective.Author advise that subtibial plateau osteotomy and joint debridement was effective in clinic.Methods:(1)From aterior medial of tibial of subplateau,in three sides:auterior,external and posterior tibia was ostcotomized in wedge shape under protecting of thick pad medial plate of articular surface was beaten for appositing osteotomy fissure.Two needles were fixed in form of cross position.(2)The osteophyma of knee,osteochondritis dissecans and changing property synovium were all excised and joint debrided.(3)The short of cartilage was pasted or transplanted through adjacent periosteum.Results:21 cases followed-up with an average period of 6～7 years,excellent and good results were 90.6%.Conclusion:The way of subtibial plateau osteotomy,joint debridement,periosteum graft and cartilage mend were uscful operation for treatment of degenerative osteoarthritis of knee joint.Author thought that the way was useful to enlarging joint compartment,reducing intraosseous pressure,recovering joint smooth surface.