In this paper, an ultra-high capacity 64-channel optical communication system using a single mode fiber is presented. The proposed system investigates the performance of optical network based on two methods of Duo-Binary modulation format at 10, 20 and 40 Gbps bit rates and distance of 1500 Km. Performance of the proposed under different modulation formats has been studied. The simulated results show that two methods are efficient. Also, the first method of Duo-Binary modulation format in ultra-high capacity optical network at 40 Gbps bit rate has better performance. It is proved that quality factor and bit error rate are function of fiber length.