Abstract: With increasing integration of electronic products, the heat dissipation problem of the power device and the large-scale integrated circuits (LSIC) becomes more and more prominent. In electronic product design, the thermal grease is usually used to realize effective heat conduct from heating device to cold plate and thereby to realize heat dispersion. The performances of the selected thermal conductive pad and thermal grease are tested and compared first in this paper. Then these performances are judged through thermal resistance test, solvent resistance test, conformal coating paint test and low temperature resistance test. The feasibility of replacing thermal grease with thermal conductive pad on PCB assemblies is analyzed, too.