NorthEastern part of India including Northern part of West Bengal is a hotspot of most of the orchids which represents more than 70% Indian orchid species. Amongst 103 species of Dendrobium, 82 are found in this region. As we know, orchid populations are depleting day by day due to the anthropogenic activities and change in climate, a suitable measure is required to predict the current situation and to conserve the valuable species. Realizing the importance of this genus, efforts were presently made in estimating the species richness of Dendrobium collected from the different parts of NE Himalayan states and parts of Eastern Himalaya with the help of DIVA GIS (geographic information system) software. Morphological characters of the different species were correlated to the environmental factors. Most of the species of Dendrobium (approximately 80%) are available at 1000-2000 m altitude with a suitable temperature variation of 10-25°C and 1000-3000 mm rainfall zone. The species richness is higher in Central Meghalaya, parts of North Bengal, parts of Arunachal Pradesh, and parts of Upper Assam.