Abstract: Optical transport network based on WDM is the best solution for next generation’s network The core of the architecture design for package switch optical transport network is the issue of optimized virtual topology design Described in this paper are the main characteristics of the issue, and a set of principles for optimized virtual topology design on wide area optical transport network are presented The objective of optimization is to maximize the throughput while minimizing the delay An algorithm using Prufer number is adopted to generate a group of feasible virtual topologies, and a heuristic algorithm for embedding the virtual topology to a given physical fiber network is also given A genetic algorithm （GA） is used for optimization and achieving the optimal solution The issue of optical transport network design is of great practical importance, so the algorithm presented provides significant guidance for practitioners