Abstract-The propagation properties of a Lorentz-Gauss vortex beam in a turbulent atmosphere are investigated. Based on the extended Huygens-Fresnel integral, the Hermite-Gaussian expansion of a Lorentz function, etc., analytical expressions of the average intensity, effective beam size, and kurtosis parameter of a LorentzGauss vortex beam are derived in the turbulent atmosphere. The spreading properties of a Lorentz-Gauss vortex beam in the turbulent atmosphere are numerically calculated and analyzed. The influences of the beam parameters on the propagation of a Lorentz-Gauss vortex beam in the turbulent atmosphere are examined in details. Upon propagation in the turbulent atmosphere, the vale in the normalized intensity distribution of a Lorentz-Gauss vortex beam gradually rises. The rising speed of the vale is opposite to the spreading of the beam spot. When the propagation distance reaches to a certain value, the Lorentz-Gauss vortex beam in the turbulent atmosphere becomes a flattened beam spot. When the propagation distance is large enough, the beam spot of the Lorentz-Gauss vortex beam tends to be a Gaussian-like distribution. This research is beneficial to optical communications and remote sensing that are involved in the single mode diode laser devices.