【Objective】The objective of this experiment is to reveal the effects of phenolic substance contents and PAL,LOX activities in soybean leaves under elevated O3 concentrations,which will provide a basis at the molecular level for the adaptive mechanism of secondary metabolism in plant.【Method】 Open-top chambers(OTCs) were utilized to investigate the effects of phenolic compounds and antioxidant ability in soybean leaves under different O3 concentration at(80±10 nmol·mol-1 and 110±10 nmol·mol-1).【Result】 The r...