Abstract: The extraction conditions of yellow pigment from Oenothera brennis.L flower were studied.The extraction effects by pure ethanol,95％ alcohol,ether,acetone,ethyl ethanoate,petroleum benzene were compared,and the result indicated that 95％ alcohol was the optimum solvent.the maximum absorption wavelength(λmax) of the 95％ alcohol being 394 nm.Mono-factor experiments and orthogonal experiments showed that the experiment temperature could have a greater impact on extraction of the yellow pigment than the ratio of the solvent to petal and extraction time of solvent.The result showed that the optimum conditions are the following:the extraction reagent 95％ alcohol,the petal and 95％ alcohol  were put in container with the ratio of 0.2∶30(g/mL) then heated at 60 ℃ for 4 h.

Key words: Oenothera brennis L.flower, yellow pigment, extraction technology