Abstract: The complex rubber of the carrageenan / locust bean gum soft capsule was taken as the research objective and the water vapor permeation,permeation of oil,tensile strength of the rubbber was taken as the measurement indexes.On the basis of single factor experiments,Box- Benhnken central composite design principle and response surface analysis were made use of to study the influence of each variable and their interaction on the response value,simulate quadratic polynomial regression equation of prediction model. The optimum complex gum( carrageenan∶ locust bean gum = 7∶ 3) content was 2.95%,plasticizer( glycerol) content was 1.54%,drying time 4.3 h was determined.Under this condition,the water vapor permeation,permeation of oil,tensile strength were 0.4821 g·mm / m²·h·KPa,0.0228 g·mm/m²·d,38.01 MPa,all closing to theoretical predicted values.It was indicated that the regression equation after response surface optimization had a certain practical significance.