In the investigation of the temporal feature for a laser beam propagating through a turbulent atmosphere, in general, the Gaussian beam wave can not be treated simply as a plane or a spherical wave. The high-frequency spectrum (HPS) is affected by the receiver aperture, the turbulence spectrum in the dissipation range, and the Gaussian beam type. The HFS departs from the ordinary behavior in a deeper tendency with the increase of the receiver aperture. For a plane or a spherical wave, the HFS departs from the 一 8/3 power law and trends to a — 11/3 power law when the aperture is as large as the Fresnel length. With the increase of the turbulence inner scale and the wind speed the HFS departs from the ordinary power law in a deeper tendency. When the Gaussian beam can not be treated as a plane or a spherical wave the HFS presents a — 8/3 and a — 14/3 power-law dependence in two regions or a unique — 14/3 power-law dependence. The results are verified by experimental data.