Objective To evaluate the effectiveness of ultrasonic diagnosis of sinus pericranii in children. Methods From October 2012 to June 2017, 18 cases of sinus pericranii confirmed by surgery were reviewed retrospectively and their ultrasonic features were analyzed，and compared with the results of CT. Results Two-dimensional ultrasound of 18 cases (100%) showed reducible cystic mass under the scalp before surgry., which disappeared with probe compression. Mass in 13 cases（72%）had a close relationship with the periosteum, and cortical depression or defect could be observed under the mass. Of 16 cases （88. 9% ）, slow velocity venous blood flow inside the mass was found. It could be observed that the blood vessels inside the mass connected to the intracranial veins through the defect of the cortex in 10 cases(55.6%). CT plain scan in 18 cases (100%) revealed extracranial soft tissue masses. Skull thinning、defect or skull destruction in 15 cases of bone window，in 12 cases (66.7%), CTA showed local abnormal vessels communicating with the dural venous sinus through the lamellar barrier vein or the conductive vessel.Conclusion Ultrasonic diagnosis of sinus pericranii was effective ,screening imaging methods as the first choice for this disease and could provide reliable imaging information before surgery. Diagnosis of difficult cases should be combined with CT examination