The propagation of truncated Gaussian beams through atmospheric turbulence is taken as an example. The analytical results (i.e., the intensity distribution, the second-moment beam width, power in the bucket and β parameter), which are obtained by using the quadratic approximation of Rytov′s phase structure function and complex Gaussian expansion method, are compared with those obtained by using numerical simulation and experimental methods. It is shown that the analytical results are nearly in agreement with those obtained by using numerical simulation and experimental methods. In addition, reasonable explanations to differences between different methods are also given.