Abstract: Thermally conductive composites were prepared with the polyamide 6（PA6）as matrix and hexagonal boron nitride（BN）and magnesium oxide（MgO）as fillers.Keeping the dosage of fillers at 50%, the effect of weight ratio of MgO to BN, thermal conductivity（λ）, mechanical properties, melt flow rate was studied. With increasing weight ratio of MgO to BN，thermal conductivity，tensile strength, and blending strength of the composites increased，while the impact strength and elongation at breaking decreased. Besides, the melt flow rate increased first, and then reduced.

Key words: polyamide, boron nitride, magnesium oxide , thermal conductivity