Abstract: C/C composites with PyC-TaC-PyC multi-interlayers (TaC-C/C) were prepared by the isothermal chemical vapor infiltration and impregnation and carbonization. Their ablation properties were tested with an oxyacetylene flame. Compared to the C/C composites，the ablation-resistance property of 3vol% TaC-C/C composite is not improved；14vol%TaC-C/C composite can withstand a long time in the oxyacetylene flame. After ablation for 20s in the oxyacetylene flame，the composites are mainly composed of C，TaC，(Ta，O) and Ta₂O₅ phases. The ablation morphologies of 3vol%TaC-C/C composite are mainly composed of the white ablation spot (5～20s) and the ablation concave (120s)，while the ablation morphologies of 14vol%TaC-C/C composites are composed of the ablation spot (5s)，a perfect oxide layer (20s) and the ablation concave (120s). The cross section of 14vol%TaC-C/C composites consists of a surface oxide layer，transition region and matrix region after ablation for 20s，which can protect carbon phases in composites fairly.