Background & Aim: This experiment investigated the effect of foliar application of methanol and ethanol on the biomass yield of medicinal plant Echinacea purpurea. Purple coneflower is an herbaceous perennial in the Asteraceae family that is used in therapy of respiratory tract infection and bacterial otitis.Experimental: This experiment was conducted in randomized complete block designed with 15 treatments and 3 replications in institute of medicinal plant (ACECR) in Karaj region in spring in 2010. The following is the treatment of this study: aqueous solution of methanol with levels of (10, 20, 30, 40, 50%), and aqueous solution of ethanol with levels (10, 20, 30, 40, 50%), and aqueous solution of mixed ethanol and methanol with the levels of (5, 15, 25%), and distilled water treatment and control treatment without spraying.Results & Discussion: The result of this study indicated that the effect of treatments on 23 evaluated index has significant difference (p<0.01).Maximum of plants height, stem diameter, capitule diameter, leaf length, leaf width, root fresh weight, root dry weight, stem dry weight, leaf dry weight, length of root, numbers of stem's leaves, fresh plant weight, and dry plant weight related to foliar application of 40% methanol, and the maximum of number of stem' s, shoot antlers of root, leaf area, chlorophyll (SPAD) were obtained by foliar application of 30% methanol, also capitule fresh weight, seed weight, and capitule dry weight was obtained by solution of 50% methanol, and diameter of root and thousand seeds weight was obtained by 50% ethanol, and maximum number of capitule was obtain by foliar application of 40% ethanol.Industrial and practical recommendations: Allgemein in this study can be concluded that foliar application of alcohol solution such as methanol and ethanol source and the bio stimulate can increase the biomass of purple coneflower.