Abstract: In a B-R buffer medium of pH 6.50, the fluorescence intensity of rhodamine B (RB) was enhanced by fluorescence resonance energy transfer between acridine orange (AO) and RB in the presence of sodium dodecyl sulfate (SDS), and the fluorescence intensity of AO-RB systems was quenched by addition of moxifloxacin (MXFC). Based on these facts, an indirect method for the determination of MXFC in tablets by the fluorescence quenching of AO-RB was proposed. Linear relationship between values of ΔF and mass concentration of MXFC was found in the range of 1.00-10.0 mg·L-1, with detection limit (3S/N) of 0.039 mg·L-1. The proposed method was applied to the analysis of MXFC tablet, and the results obtained were in consistency with those obtained by HPLC. Values of average recovery found was 99% with RSD′s (n=5) less than 0.9%.