The main purpose of the project is to study the onset and growth of superfluidity in a thin 3He/4He mixture film (wall film) near the surface of a container. The main experimental technique is to use a thin quartz crystal immersed in a liquid ³He/⁴He mixture, vibrating in a transverse mode at frequencies near 25M, 35M and 105MHz. By measuring the resonant frequency and peak amplitude as a function of temperature from 0.5 K to 1.5 K, the acoustic impedance of the mixture can be obtained. The experimental results can be used to study the superfluidity properties of the wall film. A capacitor in the experimental cell has been used to measure the dielectric constant of the mixtures for reference. Experiments have been conducted having mixtures with ³He mole fractions of 0.750, 0.705, 0.6735 and 0.644. Results are analyzed based on dynamic Kosterlitz-Thouless theory and local continuum theory. The analysis shows that the wall film has a dynamic Kosterlitz-Thouless type superfluid transition and can be treated as a quasi-2D system. The results of simulation based on a modified hydrodynamic model show good agreement with the experimental results.