Objectives: We aimed to observe the echo texture expression of the deep branch of radial nerve，search for the standard scanning section by using ultrasound, which in those ultrasound sections, including cross section and longitudinal section, the deep branch of the radial nerve get in and out of the supinator muscle. And in those most common compression areas, measure the inlet and outlet diameter of the deep branch of the radial nerve. Methods: Firstly, through 101 volunteers’ ultrasound scanning, observe the echo texture expression of the deep branch of radial nerve, and meanwhile，find out the inlet and outlet of the deep branch of the radial nerve pass through of the supinator muscle, confirm standard scanning section, including cross section and longitudinal section. Secondly, in cross section and longitudinal section of ultrasound, measure the inlet and outlet of the radial nerve diameters at the deep branch of the radial nerve enter and out of the supinator muscle, and note down the inlet and outlet measurements. Results: In ultrasound, the deep branch of radial nerve show as hypoechoic nerve, the mean anteroposterior nerve diameters of the deep branch of radial nerve where enter and out of the supinator muscle are 0.1085cm，0.1087cm, The inlet and outlet normal reference range of the deep branch of radial nerve anteroposterior nerve diameters are 0.0773~0.1397cm，0.0786~0.1388cm, those Measurements can be used for the normal anteroposterior nerve diameters of the deep branch of radial nerve in those ultrasound scanning section. Conclusions: High-frequency ultrasound is useful for detect The deep branch of the radial nerve enter and out of the supinator muscle, it can not only confirmed standard scanning section, including cross section and longitudinal section, but also detected the mean anteroposterior nerve diameters of the deep branch of radial nerve where enter and out of the supinator muscle. And the measurements can be used for diagnosis the deep branch of the radial nerve syndrome compression by the arcade of Frohse of the supinator muscle.