Khao Sok is named after its highest peak that rises to 960 meters and is the largest rainforest range on Thailand's southern peninsular. The park was officially established in 1980 with an area of 738 square kilometers, mostly sparse with limestone forests and crags. With boundary adjacent to wildlife sanctuaries of Khlong Saeng and Khlong Naka, Khao Sok is regarded as an important and valuable natural reserve. The dense forested regions of the park abound with numerous streams and waterfalls are shelter of many kinds of mammals like elephant, tiger, wild boar, bats, gibbons, samba deer, including such rare species as golden cat, Malay tapir and clouded leopard.

Khao Sok is always an attractive place for keen birders with more than 180 species recorded. Five species of hornbills and some thirteen species of woodpeckers are found here.

Attractive birds include:
Great Argus, Malaysian Peacock-Pheasant, Crested Fireback, Lesser Fish Eagle, Helmeted Hornbill, White-crowned Hornbill, Wreathed Hornbill, Blue-banded Kingfisher, Red-crowned Barbet, Brown Barbet, Red-billed Malkoha, Banded Broadbill, Black-and-Red Broadbill, Black-and-Yellow Broadbill, Buff-rumped Woodpecker, Crimson-winged Woodpecker, Chestnut-naped Forktail, White-crowned Forktail, Pin-tailed Parrotfinch, Asian Paradise-Flycatcher, Purple-naped Sunbird, etc.