As the recent trends for microelectronic devices have been higher integration and miniaturization, heat treatment of them also has become important. High thermal conductivity composite is commonly made of solid powders which have high thermal conductivity and polymer for good processibility. However, this composite had shown bad processibility as solid powder’s fraction had to be high to get high thermal conductivity. In this study, we made high thermal conductivity composite by using liquid metal, EGaIn instead of solid powder to achieve both high thermal conductivity and good processibility. By vortexing mixer, 90 vol % EGaIn high internal phase emulsion (HIPE) was made and thermal conductivity, rheological property and electric insulation of HIPE were assessed. The results suggest new concept of method for making high thermal conductivity composite and could show strength of EGaIn HIPE in accomplishing both high thermal conductivity and good processibility when it’s applied to real microelectronic devices.