Relationships among East Asian, North American and European Laetiporus sulphureus s. lat., a cosmopolitan brown rot species complex, were assessed with phylogenetic analyses and incompatibility tests. Three East Asian taxa, Laetiporus cremeiporus sp. nov., Laetiporus montanus and Laetiporus versisporus, are described and illustrated as well as compared with related taxa from Southeast Asia, North America and Europe. Phylogenetic analyses showed that L. cremeiporus and L. versisporus are clearly distinct species among Laetiporus taxa. The three conifer inhabiting species, Laetiporus conifericola, Laetiporus huroniensis and L. montanus, are closely related to each other. The European population of L. montanus exhibits two sequence variants of the EF1alpha: one is the same as observed in L. sulphureus in Europe and the other is that observed in East Asian population of L. montanus. A key to the known species of Laetiporus in the northern hemisphere is provided.