Abstract: Taking equivalent circuit model of two coils of magnetically-coupled resonant wireless power transmission system as example, the paper detailedly analyzed influence of parameters of resonant coil such as coil radius, wire radius and coil turns on inductance and quality factor at no-load state of the resonant coil. It got optimal parameters of the resonant coil as follows when power frequency is 13.56 MHz: value of the inductance is 2.634×10-5 H, value of distributed capacitance is 5.229×10-6 μF, the coil radius is 50 mm, the wire radius is 1.05 mm and the coil turns are 10. The optimal results have a certain reference value for research of magnetically-coupled resonant wireless power transmission system.