In this paper, the uniform flow of an incompressible, axi-symmetric, viscous fluid over a stationary impervious sphere with interface slip on its surface is considered. Homotopy Analysis Method (HAM) is used to solve the non linear momentum equations for stream function. To match with the uniform flow far away from the sphere, stream function is taken in terms of Gegenbauer polynomials. The solution obtained is found to be convergent and is seen to be in good agreement with the results available in literature. Drag acting on the sphere due to the flow and vorticity functions is found. For different values of the slip parameter, drag acting on the sphere is evaluated and the results are in good agreement with the available experimental data for the Reynolds numbers less than 50. Expansion of Gegenbauer polynomials and solution of the problem are obtained using MATHEMATICA.