We report a new approach to fabricate electrospun polymer nonwoven mats with porous surface morphology by varying the collector temperature during electrospinning. Polymers such as poly(L-lactide) (PLLA), polystyrene (PS), and poly(vinyl acetate) (PVAc) were dissolved in volatile solvents, namely methylene chloride (Me) and tetrahydrofuran (THF), and subjected to electrospinning. The temperature of the collector in the electrospinning device was varied by a heating system. The resulting nonwoven mats were characterized by using scanning electron microscopy (SEM), field emission SEM (FESEM), and atomic force microscopy (AFM). We observed that the surface morphology, porous structure, and the properties such as pore size, depth, shape, and distribution of the nonwoven mats were greatly influenced by the collector temperature.