Fine grained Al-5083 alloy produced by equal channel angular pressing (ECAP) at $120^{circ}C$ was tested for investigating mechanical properties and crack growth propagation behavior. Also, FEM stress and strain analysis for the samples during ECAP were investigated, using a plastic deformation analysis software DEFORM 2-D. Coarse grained as-received samples exhibited UTS of 255.6MPa with a elongation to failure of 34.4%. By contrast, the ECAPed fine grained samples exhibited UTS of 362.0MPa with a elongation to failure of 12.9%. Fatigue crack growth resistance and threshold of fine grained samples were lower than that of as-received coarse grained samples. The higher fatigue crack growth rate in the fine grained ECAPed samples may partially arise from small roughness closure effect due to smoother fracture surfaces.