There are 1076 species of plants of which 92 are orchids having similarities to the Northern and Southern Indian orchids. Seven percent of the Indian species of flowering plants and eight percent of orchids of India are found in Simlipal. Northern Tropical Semi Evergreen Forests extend over an area of about 80 Sq.km. Northern Tropical Moist Deciduous Forests extend over an area of about 1540 Sq.km. It is found all over Simlipal except the moist valleys on the Southern and Eastern aspects of the hills.
Forty-two species of mammals, 242 species of birds and 30 species of reptiles have been recorded so far in the Reserve. Panthera tigris, Panthera pardus, Elephas maximus, Bison bison, Tetracerus quadricornis etc. are found in different levels of abundance. Mellivora capensis, Pholidota, Ratufa indica, Rusa unicolor, Axis axis etc. also occur in the Reserve.