The cavity field spectrum of an atom interacting with two-mode fields in the presence of Stark shift is investigated. The cavity field spectrum expression of the system with the cavity fields in photon number state is given. Some numerical results are presented. The effects of Stark shift on the frequency and intensity of the spectrum structure are obvious, when the initial fields are weak. The symmetry of the spectrum was broken by the Stark shift and a complex spectrum structure appears. When the two-mode fields are both strong, the effect of Stark shift on the spectrum is weak. When the field I is vacuum, and the initial intensity of field Ⅱ is increasing, the higher-frequency peak of field Ⅱ is heavily depressed by Stark effect. While, lower-freqnency peak is depressed for weak initial field, and enhanced for strong initial field. When field I is vacuum and field Ⅱ is much stronger, mode Ⅱ spectrum show a single classical resonant fluroscent spectrum.