An ultra-performance liquid chromatography-tandem mass spectrometric(UPLC-MS/MS) method was developed for the simultaneous determination of indole-3-acetic acid(IAA) and its three oxidative products, indole-3-methanol(ICI),indole-3-carboxaldehyde(ICA) and indole-3-carboxylic acid(IFA) in corn(Zea mays L.) leaves. The results showed that the detection limits for the four compounds were in the range of 0.002-1.63μg/kg, and the quantitation limits were 0.007-5.43μg/kg. The recoveries ranged from 89.5% to 95.3% with RSDs of 2.3%-5.1%. The method was applied in the determination of the contents of IAA,ICI,ICA and IFA in corn leaves with their results of (196.25±7.10),(26.21±2.13),(18.65±2.02),(13.62±2.06)μg/kg, respectively. Meanwhile, the proposed method was also successfully applied in the analysis of wheat(Triticum aestivum L.),pea(Pisum sativum L.) and bristly starbur(Acanthospermum hispidum DC.),which indicated that the method had a good generality.