The cavity field spectrum of a pair of two-level atoms coupled by dipole-dipole force in a ideal cavity with two-mode radiation field is studied.It is found that the field intensities of one mode do influence the spectrum of another mode.Three-peak structure appears when two mode cavity fields are all strong and all in pure number states or in coherent states initially.If fields intensities of two mode are different,single-peak structure appears for strong field mode and three-peak for weak one.However,squeezed vacuum fields exhibit rather different features showing the classical resonance fluorescence spectra at large .