In this research we studied the relationship between the optical conductivity Ϭop and photon energy (hν), the absorbance coefficient (α), transmittance (T), the refractive index (no), and the real part and imaginary part of dielectric constant (εr, εi), the spinning velocity of deposition device (v), for a specific wave length (600nm), for a pure thin film prepared from an organic polymer material, Polystyrene (PS), by spin coating technique, on three velocities ( 1000-2000-3000)RPM, in room temperature and 1atm. It was shown that the PS film is a transmittive film with a transmittance values reach ( 85 – 90 )% in the infrared region, and the optical conductivity Ϭop increased with the photon energy, and for the velocity 1000RPM it took the highest value ( 1.67 X 1014 )1/sec, at the photon energy (hν =3.1 ev) and the wave length ( λ= 400nm ), which means that the optical conductivity Ϭop is active in the visible region, and also it decreases with the spinning velocity. The values of energy gap for allowed direct transitions were (2.5ev), (2.4ev), (2.3ev) for the films prepared on 1000RPM, 2000RPM, 3000RPM, and for the forbidden direct transitions were (2.3ev), (2.2ev), (2.1ev) respectively . The biggest value of Urbach energy Eu was (163mev) on the velocity 1000RPM and the lowest value was (109mev) on the velocity 3000RPM.