Objective To evaluate the application of high-frequency ultrasound in the detection of long head of biceps tendon and bicipital groove in patients with hemiplegia-secondary complex regional pain syndrome. Methods From February, 2013 to October, 2015, 55 patients with hemiplegia-secondary complex regional pain syndrome were enrolled. The thickness and cross-sectional area of long head of biceps tendon, and the width and depth of bicipital groove in healthy and affected sides were measured and analyzed comparatively with the clinical stages. Results The thickness and cross-sectional area of long head of biceps tendon became thin and reduced significantly, and the width and depth of bicipital groove became narrow and shallow in the affected sides at stages II and III (t>2.055, P<0.05); while no significant difference was found between two sides at stage I (P>0.05). Conclusion High-frequency ultrasound could clearly display the long head of biceps tendon and bicipital groove, and detect the morphological change, that can be helpful for rehabilitation.