The spectrum properties of partially coherent beams propagating in turbulent atmosphere are studied. Basing on the extended Huygens-Fresnel principle, an analytical propagation formula for the cross-spectral density of partially coherent beams in turbulent atmosphere is derived. The degree of spatial coherence and spectral shift of partially coherent beams through turbulent atmosphere are analyzed by using the derived formula. The results show that the spectrum of the partially coherent beam on axis in turbulent atmosphere is blueshifted in the beginning, the mount of the shift firstly increases, afterwards decreases, and finally a red shift appears with the increase of propagation distance. The lower the beam coherence is, the farther propagation distance is needed when red shift appears. At first the degree of spatial coherence increases, then decreases and approaches to zero finally. Comparing with the propagation of the partially coherent beam in free space, the atmospheric turbulence has small influence on the spectrum properties of the partially coherent beam in a short distance propagation, while has a strong influence on it in a sufficient long distance propagation.