本文以“5.12”北川地震重度受损档案调查为例,采用分层等距抽样方法 ,分别对民国时期和建国后档案的受损类型和数量进行了调查分析。调查数据显示灾害档案受损类型为12种,其中档案纸张变形占首位,其后分别为字迹受损、霉斑污染等类型。调查精度表明各受损类型的统计误差大都在15%以内,证明分层等距抽样调查方法是一种行之有效、精度较好的调查方法。 In this paper, a case study of heavily damaged Archives of “5.12 ” Beichuan earthquake is taken as an example. The stratified isometric sampling method is used to investigate the types and numbers of damaged archives during the Republic of China and the founding of the People’s Republic of China. According to the survey data, there are 12 types of disaster file damage, of which the distortion of archival paper occupies the first place, followed by the types of damaged handwriting and mold stain respectively. The accuracy of the survey shows that the statistical errors of each type of damage are mostly within 15%, which proves that the method of stratified isometric sampling is an effective and accurate survey method.