ABSTRACT objective To detect the value of high frequency ultrasound for assessment of primary frozen shoulder. Methods Retrospective analysis of 86 cases of primary frozen shoulder patients with 91 shoulder joints and 147 shoulder pain patients with 162 shoulder joints, compare the thickness of inferior capsule(IC), coracohumeral ligament(CHL), blood flow in rotator cuff interval, and the abnormality of ankle joint,long head of biceps (LBH)tendon sheath , subacromial-subdeltoid bursa (SASD) between the two groups,discuss the value of indicators for the diagnosis of primary frozen shoulders individually and in combination. Results There were differences in the thickness of IC, CHL between the tow groups，as well as the effusion around biceps tendon ,the low back echo and blood flow in rotator cuff interval (P<0.05). There were statistically significant differences in the thickness of IC，CHL and the low back echo in rotator cuff interval between the two groups with logistic regression analysis (P<0.05). The ROC curves of the frozen shoulders were compared with these three indicators. The area under the curve (AUC) was 0.939, 0.921and 0.861, respectively. The sensitivity was 92.0%, 85.1%, and 82.8%, respectively. The sexes were 92.7%, 90.1% and 89.4%, respectively; the combined diagnosis AUC was 0.985, the sensitivity was 97.7%, and the specificity was 97.4%. Conclusion High-frequency ultrasound can provide a diagnosis basis for patients with primary frozen shoulder through the thickness of IC,CHL and the low back echo in rotator cuff interval. The thickness of IC is the highest diagnostic value, and the combined diagnosis of these three indicators is of higher value.