The spatial variation of a non-uniform glow discharge due to the different diameters of the same discharge tube on the plasma parameters is attracting a considerable attention. For this reason the fundamental spatial plasma parameters of an argon. glow discharge have been measured by using fast three couple of Langmuir double probe (TCDP) technique. The orbital motion limited (OML) theory has been used, since the probe radius is smaller than Debye length xi < 1. The axial and radial variation of the electron temperature and density have been investigated. The results can be summarized as follow: due to the rise in the space-charge confinement with decreasing the tube radius and discharge current, the space-charge density increases, the electron temperature decreases.