WDM network model with distinguishing feature of nodes' functions is described for the problem of routing and wavelength assignment, and the concepts of equivalent wavelength arc, equivalent wavelength networks and equivalent multicast tree are presented Based on this model and relevant routing and assignment of wavelength (RAW) strategy, a multicast routing and wavelength assignment algorithni is put forward, which is a fast and effective algorithm. Finally, the algorithm's complexity, and point out the superiorities and drawbacks of the algorithm is analyzed.routing and wavelength assignment; multicast routing algorithm