Abstract: This paper proposes an Adaptive Sub-Path Protection algorithm for multi-granularity traffic in WDM networks. The idea of ASPP is to partition each working path into several sub-paths, and to calculate their protection paths under shared risk link groups constraints respectively. Based on dynamic traffic with different load, the performance of ASPP has been investigated via simulations. The results show that ASPP can make the tradeoffs between the restoration utilization and recovery times.