Abstarct: Today, optical networks are widely used in the transmission of Internet، telephony and television signals. This proliferation of optical networks has led to the massive flow of information in these networks, that lack of proper management of which could disrupt the transmission of packets. For this reason, routing and wavelength assignment in optical networks has become one of the most important challenges in recent years. Optimum routing in optical networks improves the outflow، efficiency and does not cause bottlenecks. In this research, a new algorithm for routing and wavelength assignment baxsed on multi-objective genetic algorithm is proposed. The target function such as delay، wavelength and the packet loss rate to evaluate the chromosomes is considered. These target functions examine the quality of service ، delay and the proper wavelength of the path selection with the lowest wavelength for sending. Sorting the response This is done using the PARETO method that reports the list of optimal responses. Implementation of the proposed algorithm in MATLAB software and different scenarios are considered in order to evaluate the accuracy of the proposed routing algorithm. Laboratory results have proved that multi-objective evaluation of responses will cause the answers found to be closer to the optimal responses