ABSTRACT Objective To investigate the different vascular effect of rabbit VX2 tumor induced by diagnostic ultrasound combined with microbubbles(MB). Methods Forty rabbit with VX2 tumor were treated by diagnostic ultrasound with different strengths of Mechanical index(MI)0.3,0.7,1.4 with MB as experiment group(n=10, n=10,n=10) and negative control(n=10) for 5 minutes. 0.1ml microbubbles in 5 ml normal saline was used as a therapeutic dose.The tumor blood perfusion was imaged with contrast-enhanced US (CEUS) before and after treatment which were analyzed by the contrast analysis software of VINNO 70. After the treatment, the tumor samples were collected for pathological examination. Results The PI in MI=0.3 increased after treatment, the PI and AUC of MI=1.4 decreased after treatment.Conclusion Low-intensity diagnostic ultrasound (MI=0.3) combined with microbubbles can enrich the blood perfusion of VX2 tumor in rabbits, and high-intensity diagnostic ultrasound (MI=1.4) can decrease the blood perfusion.