Objective To investigate the mechanism of haemostatic effect induced by microbubble(MB)enhanced therapeutic ultrasound(TUS)on splenic trauma. Methods 14 healthy dogs were divided into 3 groups.Six animals were treated by microbubble-enhanced therapeutic ultrasound(MEUS),the other eight animals were treated with TUS only group(n=4)and the MB only(n=4)served as the controls.The spleens of all animals were surgically exposed and a 20 mm long,5 mm deep incision was created on the spleens using scalpel.Contrast enhanced ultrasound(CEUS)was performed to assess the blocking effects of splenic circulation.The targeted spleens were harvested for pathological examination. Results A non-enhanced or perfusion defect region was formed within the treated area.The histological results showed splenic sinus hyperemia,microvascular hyperemia,perivascular tissue edema,platelet aggregation and intravascular thrombosis. Conclusion The mechanism of haemostatic effect on splenic trauma by microbubble enhanced ultrasound maybe intravascular thrombosis,microvascular hyperemia and perivascular tissue edema oppression simultaneously.