The Chitwan valley is characterized by tropical and subtropical forests. Roughly 70 percent of park vegetative cover is Sal (Shorea robusta) forest, a moist deciduous vegetation type of the Terai region. The remaining vegetation types include grassland, riverine forest and Sal with Chir pine Pinus roxburghii. The later occurs at the top of the Churia range. The riverine forests consist of Khair (Acacia catechu), Sissoo (Dalbergia sissoo) and Simal (Bombax ceiba). The grasslands are mainly located in the floodplains of the rivers and form a diverse and complex community with over 50 different types of grasses including the elephant grass (Saccharum spp.), renowned for its immense height. It can grow up to 8 meters in height.
A total of pdf 68 species of mammals, 56 species of herpetofauna and 126 species of fish have been recorded in the park. The park is especially renowned for its protection of One Horned Rhinoceros, Royal Bengal Tiger and Gharial Crocodile. The park harbors not only the world’s largest terrestrial mammal (wild elephant) but also the world’s smallest terrestrial mammal (pygmy shrew). A total of 544 species of birds has been recorded so far including 22 pdf globally threatened species including critically endangered Bengal Florican, Slender-billed Vulture, White-rumped Vulture, and Red-headed Vulture.