Based on the theory of generalized Huygens-Fresnel and the cross-spectral density matrix,the analytic expressions of mean-squared beam width of partially coherent radially polarized (PCRP) beam and Gaussian Schellmode (GSM) beam in atmospheric communication are derived.By comparing the influence of turbulence,coherence length and source wavelength on the spreading of width and angular between the two kinds of beams,it shows that the PCRP beam has superiority in atmospheric communication than GSM beam.The result shows that the propagations of the PCRP beam and the GSM beam in turbulence follow the same rules.The larger the turbulence is,the larger the spreading of width and angular is.The larger the coherence length is,then the more the effect of turbulence on the PCRP beam is,the smaller the angular spreading is.The larger the source wavelength is,then the less the effect of turbulence on the PCRP beam is,the larger the angular spreading is.But the PCRP beam is far less affected by turbulence,coherence length and source wavelength than the GSM beam,which means the spreading of width of the GSM beam is larger than that of the PCRP beam.In addition,the spreading of angular of the GSM beam not only relates to the three parameters above,but also is affected by the width of the source beam which is nothing to do with the spreading of angular of the PCRP beam.The above conclusions show that the PCRP beam is more beneficial to atmospheric communication than the GSM beam,and the study about turbulence,coherence length and source wavelength has a guiding role for the application of PCRP beam in atmospheric communication.