On the south it is bounded by the Peninsular Malaysian rain forests ecoregion.

Dipterocarps, Cinnamomum cassia, Durio zibethinus, Garcinia mangostana, Artocarpus heterophyllus, Ficus benghalensis, Gnetum gnemon, Mangifera indica, Toona sinensis, Toona ciliata, Cocos nucifera, Tetrameles nudiflora, Quercus acutissima, Ginkgo biloba, Shorea robusta, Prunus serrulata, Camphora officinarum, Tsuga dumosa, Terminalia tomentosa, Terminalia belerica, Tectona grandis, Ulmus lanceifolia and Nypa fruticans are the dominant trees, and species vary with elevation and latitude.

[3] The Kangar-Pattani floristic boundary forms the southern end of the ecoregion, and marks the boundary between the mostly deciduous and semi-evergreen forests of Indochina and the mostly evergreen forests of Sundaland and Malesia.

South of the boundary rainfall becomes more year-round without as pronounced a dry season.

The ecoregion's extensive areas of intact forests support some large mammals, include the Asian elephant (Elephas maximus), tiger (Panthera tigris), gaur (Bos gaurus), banteng (Bos javanicus), sun bear (Helarctos malayanus), leopard (Panthera pardus), clouded leopard (Pardofelis nebulosa), and binturong (Arctictis binturong).