The hole-patterned spin cast poly(styrene-alt-maleic anhydride) (SMA) films were analyzed. Comments on the mesoscopic self assembling morphology of polymer based on emulsification were presented. The SMA films were spin cast from a homogenous solution of water miscible organic solvent. The volatilization process of solvents in the spin-casting process was divided into two stages according to the boiling point and volatility of the solvents, tetrahydrofuran (THF) and water volatilization.