Severe plastic deformation (SPD) using various pass number of Equal Channel Angular Pressing (ECAP) experiment and followed heating at 400°C has been done for rod brass Cu-Zn 70/30 to investigate the operation on microstructure and hardness of the alloy. Optical microscopy and SEM are used to examine the microstructure change. Mechanical testing such as macro and micro hardness test is used in order to examine the change of mechanical properties. The grain structure of the alloy was refined from 34 μm to 2 μm after 4 passes ECAP and increased to 4 μm after post heating. The hardness of the alloy significantly increased from 78 Hv to 235 Hv after 4 passes and decreased to 135 Hv after post heating after ECAP. The microstructure and mechanical properties of the alloy was homogenous after 4 passes ECAP because the strain was found more homogenous.