Abstract: The single bubble adsorption model was used to treat the kinetics of cupric ion flotation, and a new method was suggested that the mass transfer coefficients of cupric ion flotation k2 could be caculated by the dynamic surface tension measurement. The influence of the acidity of solution on the mass transfer coefficient was studied. It was indicated that the optimum acidity was in good agreement with the experimental data.In the pH range of 2 to 5,a good linear relation between k2 and kexp.2 was found.