Proteinaceous microspheres filled with water-insoluble liquids can be obtained by using high-intensity ultrasound to irradiate the interface of two phases: oil/ aqueous protein solution. The review starts with a short introduction to sonochemistry, and then the fabrication and synthesis mechanism of proteinaceous microspheres are described in detail. During the formation of proteinaceous microspheres, the shell of protein can be cross-linked or not. For those non cross-linked protein, modifications such as electrostatic layer by layer assembly could be used to make microspheres stabilized and functionalized. Experimental conditions such as sonication time, power amplitudes and the position of sonicator probe placed at the oil-water interface as well as the ratios of oil-water on the yields, size and size distribution of proteinaceous microspheres are described in detail. Biological activity of proteinaceous microspheres is also discussed in this review. Most results indicated that proteinaceous microspheres could still maintain their biologically active. Finally the potential applications of the proteinaceous microspheres are outlined, which vary from as drug carriers, magnetic contrast agents to fluorescence labeling carriers etc. Such sonochemical method provides us a new, novel idea to preparation of polymer microspheres and will have prospective applications in biological filed etc.

Contents
1 Introduction
2 Background of sonochemistry
3 Fabrication of proteinaceous microspheres by sonochemical method
3.1 Mechanism of microsphere formation
3.2 Experimental conditions on the properties of proteinaceous microspheres
3.3 Biologically active of proteinaceous microspheres
4 Application of proteinaceous microspheres
4.1 Encapsulating drug in proteinaceous microspheres
4.2 Other applications of proteinaceous microspheres