In this research studied of Thermal Conductivity and Hardness Test of Carbon Black / Polymer Micro Composite at different weights ratios were studied. Five samples were prepared for Carbon black with epoxy resin, where the percentages of carbon black ranged between 2%, 4%, 6%, 8% and 10%. The mechanical properties of hardness test that the values of hardness for Carbon black decreasing with increased ratios of additive compared to the case of pure epoxy. For thermal conductivity coefficient (K), the results that values for Carbon black increased by increasing the ratios additive compared to pure epoxy.