Objective:To research the radiological manifestations for synovial osteochondromatosis of the knee joint. Methods:24 cases with synovial osteochondromatosis of the knee confirmed by pathology were retrospectively analyzed. All the 24 cases took CR and 18 of them took CT

10 of them took MRI. Results:There were 18 of 24 cases were confirmed by CR

17 of 18 cases were confirmed by CT

8 of 10 cases were confirmed by MRI. Different sized and numbered calcification and loose bodies were seen inside or surrounding the joints with CR. CT and MRI showed much clearer and more of the calcification and loose bodies could be seen. The thickened synovial membrane

effusion and cartilage loose bodies could be seen clearly. Conclusion:CT is more valuable for diagnosis of the diseases

and it can show some manifestations which CR and MRI could not be seen;CR is the first choice to detect the disease;MRI may be valuable for early diagnosis of the diseases.