Abstract: A new method was proposed to determine trace nickel,manganese,chromium and lead in vegetable oils by flow-injection derivative-flame atomic absorption spectrometry. The flaws that sampling is large and matrix interference is serious in conventional flame atomic absorption spectrometry(FAAS) were overcome by flow-injection sampling technique. The sensitivity and signal selectivity were enhanced when derivative technique was used in flame atomic absorption spectrometry. The results of determinations of nickel,manganese,chromium and lead in vegetable oils was satisfactory by derivative-flame atomic absorption spectrometry combined with flow-injection, which was not done by conventional FAAS or flow-injection FAAS. Their sensitivities were 0.005 4 μg/mL,0.003 4 μg/mL,0.006 7 μg/mL,0.025 μg/mL respectively,the relative standard deviation was in 0.3%～2.8%.