Abstract: This paper studied the stability of yellow pigment from Oenothera biennis L.flower in the following different additive agents:light,heat,acid,sodium hydroxide,hydrogen peroxide,reducer,metal ions,saccharose,Vc,etc.The experimental results show that the pigment can easily dissloved in the solvent of 95% ethanol,pure ethanol,acetone,ether,ethyl ethanoate etc.It has a certain stability toward light，heat，sodium hydroxide,hydrogen peroxide,metal ions(Na+，Mg2+，Ca2+) and food additives ect,however,it has less stability to solutions of hydrochloric acid,sodium sulfite,Cu2+ and Fe3+gave undesirable effects.

Key words: Oenothera biennis L., yellow pigment, stability