Assam State Zoo is located, the area covered by Hengrabari reserve forest in Guwahati the undulating hillocks in kamrup district of Assam. A study was conduct to find out the distribution, identification and availability of plant species and their ex-situ conservation. The area covered by lots of naturally occurring plant species and conservative plants with a number of diversity. Assam state zoo Botanical Garden is also one of important ex-situ conservation center of plant species of the state. Plants species are mainly tree both evergreen, semi-evergreen and deciduous, a number of climbers, herbs and shrubs which are belong to some medicinal value and economic importance also.