Dipterocarpus alatus (Thai: ?????; Khmer chh?ti雔 ba:y; chh?ti雔 t黭; chh?ti雔 thom or chheuteal; Vietnamese Dau nuoc (Dau rai)) is a tropical forest tree; of dense evergreen or mixed dense forests; common in Thailand; Cambodia; Laos and Vietnam. This species is also been found in the Philippines. It often occurs gregariously along river banks and is a key planting species for regenerating deforested land around the Dong Nai river and Cat Tien National Park. This tree is an endangered species in its natural habitat.