In this work, the surface treatment of polystyrene using the DC Pseudo-Plasma is studied. First, the DC Pseudo-plasma was employed as a function of plasma device parameters under different operating conditions including time (t) (30 s), current (I) (15mA), distance (d) (3 mm) between inter-electrodes, mesh anode transparency (T) (19 %), distance between the polystyrene sample and the mesh anode (D) (2 mm) and air pressure in plasma exposuring system (P) (2 torr). The best optimization of these parameters were performed by the water absorbency, which supported by the Scanning Electron Microscope (SEM) test Atomic Force Microscope (AFM) test.