The concentration of biologic surface active materials has a great influence on the foam properties of the solution with them. Foam properties include foaming ability and foam stability. In this work

foaming ability and foam stability were characterized by initial foam height and half-time of foam

respectively. The relational expression between the initial foam height of the solution with two surface active materials and their concentration bellow the critical micelle concentration (CMC) was determined by using the extended Szyszkowski equation and Rosen's empirical model. The relational expression between the half-time of foam of the solution with two surface active materials and their concentration bellow the CMC was established on the basis of the rules that the gravitational potential energy and the surface energy all decreased with the bubble breakup in the foam phase. An aqueous solution with bovine serum albumin (BSA) and lysozyme (LZM) was used as the simulation system to verify the accuracy of these relational expressions. The results showed that the two relational expressions could be used to accurately predict the foam properties of the solution with BSA and LZM. The effect of BSA on the foam properties of the solution was more significant than that of LZM.