Objective To explore contrast-enhanced ultrasonography (CEUS) in diagnosis renal injuries complicated with active bleeding of different velocity,and analysis the related factors of renal traumatic degree.Methods Thirty-four Ⅰ - Ⅴ grade lesions of renal injury were made in 4 dogs and 6 New Zealand rabbits.Two and three dimensional CEUS were used to observe traumatic extension,and traumatic position,involving in vascular as well.Then the injury condition was classified and assessed synthetically.Results The range of lesions observed by using 2D and 3D ultrasound had consistency with those of the pathologic sample (length-diameter:F =0.4724,P =0.6252; transverse diameter:F =1.6174,P =0.20490),3D-CEUS can display the vascular that involved by renal injury.In the same traumatic extension condition,the time of animal becoming shocked and injury severity was related to not only traumatic extension but also different velocity of active bleeding and involving in vascular.Conclusions Contrastenhanced ultrasound can objectively reflect renal injury severity,and more information can be provided to clinical for management.