Objective: To evaluate the performance of routine high frequency ultrasound in combination with dynamic tests in diagnosing pharyngoesophageal diverticulum(PD). Methods: A total of 42 cases of PD undergone routine high-frequency ultrasound (42 cases), with successive swallowing saliva test (28 cases), drinking water test (15 cases) or oral contrast-enhanced ultrasound agent (2 cases), were reviewed. The imaging features of ultrasound were compared with findings from esophagus barium swallow examination. Results: All lesions were located in the back of thyroid gland, with 39 cases (92.9%) in the left lobes and 3 cases(7.1%) in the right. Fourteen cases (33.3%) were diagnosed as PD according to the structure of hypoechogenicity wall and internal gas hyperechogenicity presented on the ultrasound imaging. Positive findings of dynamic tests included absence of liquid echogenicity, gas hyperechogenicity or contrast agent hyperechogeni-city entering into the lesions. Sequential execution of swallowing test, drinking water test and oral contrast agent test identified 11 cases (26.2%), 15 cases (35.7%) and 2 cases (4.8%), respectively, increasing the rate of diagnosis from 59.5%（25 cases）, 95.2%（40 cases） to 100% (42 cases). Two cases identified by oral contrast agent test had larger maximum diameter( 8.8 mm and 24.7 mm). Conclusions: For the mass behind the thyroid, high frequency ultrasound in combination with swallowing salivais should be routinely recommended. Drinking water or oral contrast-enhanced ultrasound may facilitate the diagnosis of PD with the diameter of mass greater than 7 mm.