Abstarct: The viscous fingering instability occur when a less viscous fluid is injecting in a porous media that filled with more viscous fluid. Onset and propagation of fingers are playing an important role in fluids displacement, especially in oil discovery from reservoirs. In this study, the viscous fingering instability in miscible displacements of Newtonian fluids and also combination of Newtonian and Non-Newtonian fluids is studied experimentally. In order to obtain more actualized results, a porous media with transparent walls and compact structure of spherical glass beads is constructed, that has close permeability to oil sand. The main purpose of this study is to investigate the effects of elastic properties on this instability with the help of Boger fluids. Boger fluids are a special group of dilute polymer solution in which the viscosity and elastic dependence are eliminated and each factor can be controlled independently. With increasing the polymer concentration, the Boger elastic properties increased and its results on this instability have been investigated. Also, the effects of other factors such as the viscosity ratio and Blake dimensionless number on the quality of growth and the shape of the fingers, as well as their effect on important physical parameters including the mixing length, sweep efficiency and noise growth to baxse state are also discussed.