Abstract: A method was used to determine the hydroxyl radical in Fenton reaction by spectrophotometry.The optimum experiment condition was developed in the phosphate buffer solution(pH 7.4),the concentrations of Fe~(2+)、H_2O_2 and 1,10-phenanthroline were 0.4 mmol/L、0.015% and 0.35 mmol/L,respectively.At the same time,the reaction solution was heated at 37 ℃ for 90 min.This method was validated by vitamin C and thiourea.The scavenging effects of Dioscoeaopposita Thunb were measured by this method.The results were sat...