Abstract: Basic principles of synthetic jet are introduced and key points of its design are pointed out.The design of two important parts:piezoelectric actuator and cavity is analyzed, the optimization of input parameters are discussed and experimentally investigated. The results show that:small \fracR_cR_m, h,m and V is good for size choice of synthetic jet, electrical input with its parameters as higher voltage, basic resonance frequency, square wave is the most efficient input for work of synthetic jet.