A new class of multifunctional nanobubble using poly(lactic-co-glycolic acid) (PLGA) has been developed as ultrasound imaging contrast agents, doxorubicin carriers, and enhancers of ultrasound-mediated drug delivery. The doxorubicin nanobubble (DOX-NB) wrapping carbon tetrafluoride gas was prepared with double emulsion method. We evaluated the enhanced ultrasonic function of the DOX-NB in vivo; its antitumor function was confirmed. The diameter of the prepared bubble was 500 nm, and the potential was -23 mV. The drug loading and encapsulation efficiency of the bubble were 78.6 and 7.4 %, respectively. Therefore, the DOX-NB greatly enhanced ultrasound imaging in vivo. Ultrasound combined with DOX-NB had significant antitumor effect. Compared with other groups, the tumor growth rate and the proliferation index were the lowest while the survival rate and apoptosis index were the highest.