A method was developed for the determination of nicotinamide(NA) in rice by prE-column derivatization and high performance liquid chromatography/electrospray ionization mass spectrometry(HPLC/ESI-MS). After extraction with water, NA was derivatized by 9-fluorenylmethoxycarbonyl(FMOC-Cl). In order to enhance the sensitivity, the derivatization was optimized regarding organic solvent content and amount of FMOC-Cl. The best HPLC conditions for the separation of NA in real samples were achieved using a C18 column and mobile phase which contained 0.1% formic acid. The MS experiments were performed in selected ion monitoring mode(SIM). The method shows good linearity over the range of 0.1-5 mg/L for NA with a correlation coefficient of 0.9983. The limit of determination(LOD) was 0.05 mg/kg. Precision and recovery studies were evaluated at three concentration levels for rice root, stem, leaf and unpolished rice. The recovery(n=5) ranged from 72.0% to 89.2% with relative standard deviations from 2.3% to 9.6%. The method is simple, highly selective and reliable, and can be used to determine NA in rice at physiological level.