Abstract: This paper proposes an algorithm, called Dynamic Shared Sub-Path Protection (DSSPP), for protecting a single Shared Risk Link Group (SRLG) failure in survivable WDM mesh networks. DSSPP firstly searches a primary path for a connection request, and it follows to segment the primary path into several equal length sub-paths according to the m, where the m is the length of the sub-path, and searches a SRLG-disjoint backup path for each sub-path. If two sub-paths are SRLG-disjoint, then their corresponding backup paths can share the common resources. When computing paths, DSSPP considers the load balance and the resources sharing degree, so that the paths are the minimum cost, and the resource utilization ratio can be improved and the blocking ratio can be reduced. The simulation results show that DSSPP not only can completely protect a single-SRLG failure but also can make the trade-offs between the resource utilization ratio (or blocking ratio) and the protection-switching time.