Abstract: Resistance-inductance-capacitance（RLC） filters are usually used at the inverter side to suppress over-voltage phenomena at the motor terminal in long distance pulse width modulation（PWM） driving system.However,there is little clear optimal method to determine the filter parameters.In this paper,a filter design method was proposed which the parameters such as cable length,cable inductance,cable capacitance,reflection coefficient,were considered synthetically.Firstly,the model of the long distance PWM driving system was founded based on transmission theory and its transfer function was educed,then the model with RLC filter was also founded and its transfer function was educed.Thus,the transfer function of RLC filter was established considering cable parameters,and the filter design method was obtained.The validity of the proposed design method was supported by simulation and experimental results.