To determine the content of nevirapine, a fluorescence quenching method has been developed. The excitation wavelength was 225 nm and emission wavelength was 340 nm. The calibration curve was linear over the range of 5.0 × 10-7 ~ 1.0 × 10~3 mol/L. Cor-relationco efficient was 0. 9946. The recovery of NVP was 102% (n = 5) and the relativestan darddeviation (RSD) was 2.4%. The RSD for intraday and interday were2.6% (n=5) and3.8% (n = 5), respectively.