Rhamnolipid, a kind of anion surface active agent, has good solubility in alkaline solution. It could reduce the aqueous surface tension evidently and change the aqueous surface tension evidently, and change the wettability of the solid surface. Also rhamnolipid exhibits multi-functions, such as emulsification, demulsification, froth breaking abstersion, decentralization, flocculation antistatic unction and lubrication. Furthermore, Rhamnolipid displays a strong ability to froth stably. At the same time it could produce increasing effect with other surface active agents because of its fine compatibility. On the other hand rhamnolipid shows less irritativeness to the human beings, with quick biodegradation.