Abstract: The method of microwave pretreatment is adopted to find the factors that affect the different extraction processes of Flos Lonicerae, and the three wavelength spectrophotometry is applied to measure the content of chlorogenic acid. The experimental results demostrate that the chlorogenic acid concentrations in 0~80 μg/mL obey linear relation with ΔA, when the absorbance was measured at wavelength λ₁=280 nm, λ₂=325 nm and λ₃=380 nm. The optimum extraction condition is the 20 mL of 70% ethanol and radiated 70 s in microwave. Comparing with the traditional method, the method requires less equipment and has reliable accuracy and good precision.