Orchids are fascinating group of angiosperms that have attracted the admiration of scientists, horticulturists, and industrialists because of their amazing ornamentation, brilliant color combinations, and extended blooming period. They are very sensitive and have high specificity towards pollution free environment of their niches and need much more care for protection of their habitat for their existence. The process of open-cast coal mining involves removal of top overlying soil layer with vegetation cover, leading to denudation and total elimination of the forest cover. Majority of the orchids are found as epiphytes and destruction of trees has created permanent elimination of these epiphytes. Assam is blessed with wide-range of eco-climatic suitability to fulfill the specific micro-climatic requirement for the growth of orchids. The present study deals with the natural diversity of orchids within Lekhapani Reserve Forest of Makum Coal Field in Digboi Forest Division under Dihing-Patkai Wildlife Sanctuary. The reserve forest covers an area of 1158.46 hectares. Lekhapani- Tipongpani Mining lease lies on the South West border with Arunachal Pradesh. Bio-geographically, the study site is situated in the Eastern Himalayan province where the major forest type is Assam Valley Tropical Wet Evergreen Forest dominated by Canarium resiniferum Brace ex King., Dipterocarpus retusus Blume., Lagerstroemia speciosa (L.) Pers., Terminalia bellerica (Gaertn.) Roxb., T. myriocarpa Van Heurck & Müll. Arg. etc. and is situated over a huge deposition of coal. Surveys and walked transects were conducted to enumerate the species and its population status. A total of 39 orchid species under 24 genera have been recorded from the study site, mostly of sub tropical and temperate environment. Amongst them, 36 species were epiphyte, 3 species were terrestrial and 6 species were found to be rare in rank. This study covered the distribution of the species, their host range, phenology, and ecological status. According to government policies, the total destruction of the forest for open cast coal mining has created a great threat for this plant resource especially the orchid flora of the Dihing-Patkai Region. With a view to conserve these species, Rain Forest Research Institute, jointly with Makum Coal fields planned the ex situ conservation and multiplication of orchids germplasm of Lekhapani Reserve Forest.Received: November