Objective To evaluate the radiological signs of synovial chondromatosis and the diagnostic value of radiology.Methods 36 cases with synovial chondromatosis confirmed by histology were retrospectively analyzed.All 36 cases underwent radiography and 13 of them underwent CT examinations,10 of them underwent MRI.Results The knee in 22 cases,hip in 5 cases,ankle in 3 cases,shoulder in 2 cases,elbow in 2 cases,carpal joint in one case and temporomandibular joint in one case were involved in 36 cases.Of them,one joint involved in 31 cases and bilateral knee joints involved in 5 cases.Multiple calcareous loose bodies with different sized(from several diameter to 2.7 cm)were seen inside or surrounding the joints on X-ray and CT images.In 10 cases with MR examination,the calcareous nodules were low signal intensity on both T_1WI and T_2WI in 8 cases.In other 2 cases,the center of calcareous nodules showed as high signal intensity while the rim showed as low signal intensity.Conclusion X-ray,CT and MRI are of significant value in diagnosis of synovial chondromatosis.