Abstract: The ethanol extraction of flavonoids from Houttuynia cordata Thunb Leaves were carried out.On the basis of single-factor tests,the orthogonal test was used in the optimization of technological parameters.Results showed that the optimum conditions are as follows:temperature 80 ℃,time 3 hours,ethanol concentration 50% and the ratio of solid to liquid 1:30.By the above conditions,the flavonoids extraction rate is more than 92%.Applying this extracting technology,the flavonoid content is increased,the results showed that this process is reasonable and practicable.

Key words: Houttuynia cordata Thunb.leafs, flavonoids, extracting process