Objective：Two gold nanoparticle-microbubble composites with different structures were constructed，which can be used as ultrasound imaging contrast agents and for photothermal conversion using the surface plasmonic excitonic effect of gold nanoparticles. Methods：One is gold encapsulated microbubble（AuMB）with gold nanoparticles encapsulated in a microbubble gas core，and the other is polyethyleneimine-gold loaded microbubble（PEI-AuMB）with gold nanoparticles loaded onto the microbubble surface by covalent bonding. These gold nanoparticle-microbubble composites were characterized for their physicochemical properties，and their ultrasound contrast capabilities were evaluated by in vitro ultrasound imaging. Their photothermal conversion ability was evaluated by in vitro photothermal experiments. Results：Both composite microbubbles showed better ultrasonography ability than blank microbubble（MB），among which PEI-AuMB showed better performance in the duration of ultrasonography enhancement；both composite microbubbles also showed superior photothermal conversion ability than gold nanoparticles alone，and AuMB had better photothermal therapeutic potential. Conclusion：All these results demonstrates that gold nanoparticle-microbubble composites are promising carrier systems for therapeutic integration.