A preliminary estimation of ablation property for carbon-carbon composites by artificial neutral net (ANN) method was presented.It was found that the carbon-carbon composites’ density,degree of graphitization and the sort of matrix are the key controlling factors for its ablative performance.Then,a brief fuzzy mathe- matical relationship was established between these factors and ablative performance.Through experiments, the performance of the ANN was evaluated,which was used in the ablative performance prediction of C/C composites.When the training set,the structure and the training parameter of the net change,the best match ratio of these parameters was achieved.Based on the match ratio,this paper forecasts and evalu- ates the carbon-carbon ablation performance.Through experiences,the ablative performance prediction of carbon-carbon using ANN can achieve the line ablation rate,which satisfies the need of precision of practical engineering fields. A preliminary estimation of ablation property for carbon-carbon composites by artificial neutral net (ANN) method was presented. It was found that the carbon-carbon composites’ density, degree of graphitization and the sort of matrix are the key controlling factors for its ablative performance.Then, a brief fuzzy mathe- matical relationship was established between these factors and ablative performance. Through experiments, the performance of the ANN was evaluated, which was used in the ablative performance prediction of C / C composites. When the training set, the structure and the training parameter of the net change, the best match ratio of these parameters was achieved. Based on the match ratio, this paper forecasts and evalua- ates the carbon-carbon ablation performance. Through experiences, the ablative performance prediction of carbon -carbon using ANN can achieve the line ablation rate, which satisfies the need of precision of practical engineering fields.