Objective: To study the spectrum-effect relationship for active Components from Taohong Siwutang(THSWD) in dysmenorrheal model mice. Method: The effects of different extracted parts of THSWD were investigated in dysmenorrheal mice mode. The corresponding parts from THSWD and its constituent herbs were chemically analyzed using GC\|MS and bioassaies were carryied out using dysmenorrheal mice mode in vivo. Regression and correlation analysis was made to discern the relationship between each peak and the pharmacologic data. Result: The petroleum ether extraction of THSWD is the active component. Unsaturated fatty acids are the essential components of THSWD. The linoleic acid as the major constituent is also significantly correlated with latency period and the frequency of writhing reaction. The 9-octadecenoic acid

eicosanoic acid and heptacosane have a certain degree of synergy on the analgesic effect. Conclusion: The data suggest that the methods are helpful for screening bioactive components from complex mixtures

such as the extracts of TCM.