Based on the propagation equation of partially coherent light,the spectral changes in polychromatic Gauss-Schell-model (GSM) beams propagating through a lens with spherical aberration are studied .It is shown that the on-axis spectrum of polychromatic GSM beams passing through the spherically aberrated lens depends on the spatial correlation parameter β, spherical aberration C4, band-width σ0 of the source and position parameter z in general. The attention is focused on the effect of spherical aberration on the on-axis spectrum and the results are compared with those for the aberration-free case. It is shown that the on-axis spectrum is blue-shifted or red-shifted in the presence of the spherical aberration, whereas there is only the blue shift for the aberration-free case. Additionally, the spectral splitting can take place. The spectrum is split into two curves with equal height, and a rapid transition appears at critical positions. Moreover, the effect of spherical aberration becomes noticeable with increasing spatial correlation. The spectral splitting vanishes if the spatial correlation parameter is less than a certain value.