Rajbanshis, as they are known in North Bengal and lower Assam, are one of the oldest ethnic groups of North- Bengal. They are the descendants of Koches with Mongoloid physiognomy. Ethnobotanical knowledge of Rajbanshis is very rich. The study designs interview with Adhikari, Mahan, culinary sharing in their own kitchen and also participation in their various social rituals and festivals. Present survey shows their all round dependency on plants for the purposes of therapy, food and material life. Ethnobotanical knowledge of wild plants is restricted to the village doctors and elderly persons. It is very essential to document their ethnic knowledge which may play a vital role in homeopathy, Ayurveda, and as an indicator of past environment and conservation of nature and natural resources.