We note that traditional markers don?t consider the long term average rate and the instantaneous rate of traffic at the same time. Therefore, they can not achieve fair sharing excess bandwidth in proportion to Committed Information Rate(CIR). To solve these problems, we propose the Innovation Three Color Marker(ITCM) algorithm. Our proposed algorithm calculates both the long term average rate and the instantaneous rate of traffic when marking the packet. Moreover, ITCM achieves the proportional fair sharing among aggregates by marking the packet as yellow with probability in proportion to CIR. We have compared the performance of ITCM with traditional markers. Simulation results show that ITCM performs better than traditional markers in the case of under-subscription. It not only achieves the target rate, but also achieves proportional fairness of sharing the excess bandwidth.