Two different micro-emulsions based on methyl meth acrylate / butyl acrylate copolymers have been synthesized to be used as retanning agents for chrome tanned leather. The main difference and characteristics of the two prepared copolymers were studied. The nano particle size of the two co-polymers was confirmed using transmission electron microscope (TEM). The characterization of the two prepared copolymers were investigated. The properties of the retanned leather, namely, physico-mechanical properties as water absorption, tear strength; tensile strength and elongation at break were measured. Thermal gravimetric analysis (TGA) technique was used to examine the thermal stability of the retanned leather. Texture of the grain surface and fibers were inspected using Scanning electron microscope (SEM). The retanned leather showed an improvement in its physico-mechanical properties, as well as enhancement of its thermal stability. Also, it has uniform dyestuff, softness and firmness grain. All these promising results provide evidence to the applicability of the prepared copolymer emulsions as efficient retanning agents.