The thermal conductive behavior of Zirconium diboride (ZrB2) coated with different proportions nanoalumina (Al2O3) in epoxy composites was investigated by the laser flash experimental and finite element analysis (FEA) methods. The coated ZrB2 composite particles were categorized into the 3-1, 3-2, 3-3 and 3-4 systems, which corresponded to four different mass ratios of ZrB2 particles to Al2O3 particles, respectively. It could be found that the coated ZrB2 composite particles were effective for increasing the thermal conductivity of the filled epoxy composites due to more effective formation of the conductive chain structure in the composites compared to the single-phase particles. In comparison, the system of 3-3 showed the most positive effect on improving the thermal conductive performance of epoxy composites. For composites with a 7 vol％ of ZrB2/Al2O3 composite particles of 3-3 system, its thermal conductivity was 0.65 W m?1 K?1, increased by 20％ and 79％ relative to single-filled composites of ZrB2 and Al2O3 with same filled content, respectively. The predicted thermal con-ductive results of Al2O3 coated ZrB2 particles in epoxy matrix obtained by finite element analysis were in rea-sonable agreement with the experimental results.