The changes in fatty acids of lard-based 1,3-diacylglycerols(DG) during heating process were analyzed by gas chromatography(GC) and relevant indicators of lipid oxidation including acid value (AV), peroxide value(POV), malondialdehyde(MDA) and carbonyl group value(CGV) were measured to evaluate the quality of lard-based 1,3-DG oil during heating. The results showed that the amount of saturated fatty acids (SFA), monounsaturated fatty acid(MUFA) and trans-fatty acids(TFAs) of lard-based 1,3-DG oil increased with increasing heating temperature and time whereas polyunsaturated fatty acids(PUFA) decreased. When the heating temperature was 210 ℃, the amount of MUFA increased first and then decreased, showing its peaks on 4 h. AV remained relatively stable while both POV and CGV values increased and the amount of CGV could not meet the national standard(50 meq/kg) after heating 6 h at 210 ℃. After heating 150, 180 ℃ for 4h or 210 ℃ for 2 h，MDA began to slide. Heating of lard-based 1,3-DG oil at higher temperature for a longer time could lead to lower quality. Therefore, 1,3-DG oil should not be heated at high temperature for a long time.