The resonance fluorescence from an intracavity three-level atom driven by two coherent lasers are discussed. Compared with the case in the free space, the spectrum in the cavity is squeezed towards or expands outwards the resonant peak, but the type,width and strength of each spectral line remains the same. The line type of the resonant peak is determined only by the detuning between the atom and driving fields. The origination of the spectral features are analyzed.