Abstract: To find out the optimum harvest time for wild Isodon rubenscens in Qi County of Henan Province and introduced in Wuhan ,Guangshui of Hubei Province,we evaluated the yield and quality of I.rubenscens by the number of ramification,weight of leaves and content of rubescensine A of per-bundle plant.In addition,the effects of climate factors on yield and quality of I.rubenscens were analyzed.The results indicate that the effect of climate factors on the quality of I.rubenscens is not prominent,the content of rubescensine A in leaves of I.rubenscens in June reach approximate peak value in three areas.But climate factors have an effect on the yield of I.rubenscens,some of these factors can lead to the number of ramification on the plant in introduction areas is upwards to 2-4 times than the original area.To analysis all research results of the quality and yield of I.rubenscens,the optimum harvest time of I.rubenscens should be fixed ahead florescence.Therefore,the optimum harvest time of I.rubenscens is fixed from June to July in the introduced area-Guangshui of Hubei Province,and from June to August in the original area-Qi County of Henan Province.The studies can provide scientific basis for the Good Agriculture Practice of I.rubenscens.