The flora of Kathmandu Valley is represented by 1500 vascular plant species, which is about 21% of the Nepal Flora. So the bio- diversity of Kathmandu Valley is very rich. At the same time, Kathmandu Valley is loosing some 18 orchids and 6 fern species due to fast urbanization, deforestation, environmental degradation and other human impacts. The study shows that 7.3% of the Kathmandu Valley flora are: threatened 3%, rare 2.2%, endangered 1.4%, and vulnerable 0.7%, So there is an urgent need to conserve Kathmandu Valley flora. For this, it is necessary to realize the appropriate policy, legislation, institutional building, and manpower support, for conservation activities and mobilizing NGOs and local people. Due to the high concentration of endangered, threatened and rare plant species in the Phulchoki and Godawari area, the area should be declared as a conservation area immediately in order to stop further degradation of valuable flora, for future generations and to maintain the ecologicalbalance of Kathmandu Valley.