Abstract: A simple, practical and sensitive method based on solid- phase micro- extraction ( SPME) with on- fiber derivatization coupled with gas chromatography mass spectrometry ( GC- MS) was developed for the analysis of aldehydes in rice.The major factors which affect the effect of SPME, such as type of the fiber, quantity of derivatization reagent, temperature and time of extraction were studied.The results showed that a 65μm PDMS/DVB fiber coating with the 10mL 60mg /L O- ( 2, 3, 4, 5, 6- pentafluorobenzyl) - hydroxylamine for 20min at 40℃ in the headspace of derivatization-reagent-vial followed by extracting for 80min at 40℃ in sample vial headspace was the optimum condition of SPME with on- fiber derivatization.The 9 aldehydes were found to be linear in the validated range with correction coefficients ( R2) better than 0.99.The limitations of detection of the method were 0.010⁰.695μg /kg in rice while the relative standard deviations ( RSD) were 5.0% ⁷.5% ( n = 5) .The recoveries of aldehydes were found to be 77.9% ~ 124.2%.This consecutive operation of this method, namely coating with the derivatizing reagent, extraction of aldehydes, injection and detection, could automatically completed on line, which made it efficient and suitable for routine analysis of rice aldehydes.Base on correlation anlysis between aldehydes and sensory evaluation scores of rice samples, it was found that hexanal and pentanal were important indices to rice quality.