The statistical performance of detecting optically rough surfaces with pulsed laser radar using energy detection techniques has been investigated in this paper. Under the far field condition, the analytical expressions for computing the speckle number integrated by the receiving aperture is presented, and the speckle number subtended by the telescope is found to be dependent only on the relative size of the laser beam waist and the area of the entrance pupil. A new statistics for photoelectron counts is proposed when the receiving telescope collects a large number of speckle cells and photoelectrons. The detection probabilities for airborne and spacebased laser radar have been derived. The results indicate that the laser radar performance is closely related to the speckle number observed by the receiving aperture and the influence of the speckle noise is abated with the increase of integrated speckle cells.