A novel Spice model of silicon-based micro-ring resonator is introduced,which can serve as a basic component of integrated optical path. Some basic applications of series-coulped structure,such as double-ring and muliple-ring filter,are analyzed. In addition,the tradeoff between optical gain and 3 dB bandwidth characteristics are investigated. Results show that the larger number of rings,more precipitous resonant peak will produce the better device filtering characteristic.