Population structure of Quercus semecarpifolia Sm. (khasru) was studied in mature forest of Shivapuri Hill (Shivapuri National Park, Kathmandu), Central Nepal from November 2002 to February 2003. A total of 16 quadrats (20 m x 20 m) for trees and 58 (5 m x 5 m) for seedling and sapling were laid from 2200 m to 2500 m on southern face of the hill. The study site had mature forest with comparatively low tree density (203 ha^{- 1}) but high basal area (50 m² ha^-1). The forest had abundant number of small seedlings (density 3807 ha^-1) but sapling was very rare (density 62 ha^{- 1}). Survival of large seedling and sapling appear to limit the regeneration of khasru forest. Size class diagram of khasru resembled bell shape with higher density of medium sized trees. So there is lack of continuous regeneration of khasru under its own canopy. Partial canopy opening by thinning of old trees may induce regeneration in old growth and mature khasru forest but long term monitoring of seedling and sapling survival in permanent plot is essential to reach any conclusion.