Abstract: UAV aerophotographic system is a new technique developed in recent years which can rapidly acquire high-resolution images. In the estimation of forest volume, it is needed to rapidly and efficiently acquire forest remote sensing image.Although the high-resolution remote sensing images can be acquired through satellite and airborne radar as well, compared with UAV aerophotographic system,the latter has lower cost on flight, short industry cycle, flexible and other advantages. In this paper, the DSM and DEM of the case area are acquired with the use of UAV aerophotographic system, tree height is extracted by maximum neighborhood method, and tree crown information is segmented by watershed algorithm. In addition, the forest volume is estimated by the two-way tree volume model with tree height and crown diameter as explanatory variables.The results show that the precision for tree height extraction is 83.73%, the precision for crown diameter extraction is 86.98%, and the estimated precision for the stand volume is 81.80%.

Key words: UAV aerophotogrammetry, tree height, crown diameter, estimation of forest volume