Extensive surveys on wood-rotting fungi were recently carried out in Hainan Province, southern China. Around 2500 specimens of poroid wood-inhabiting fungi were collected during ten field trips, and 235 polypores were identified. Four species, Grammothelopsis asiatica Y.C. Dai & B.K. Cui, Inonotus latemarginatus Y.C. Dai, Perenniporia hattorii Y.C. Dai & B.K. Cui and Wrightoporia austrosinensis Y.C. Dai, are described and illustrated as new. Of the 235 species, 99 were found from the province for the first time.