中文摘要：

目的以随机模拟法进行大量单亲累积亲权指数（CPI）统计分析。方法针对Identifiler、PP18D、PP21、AGCU EX20、AGCU 21＋1等5个试剂盒,使用自主研发软件,随机模拟100万组单亲组合并计算单亲PI,统计各试剂盒单亲极低CPI比率（R_（VLCPI））、各基因座的PI中位数（M_（PI））和39个基因座的平均单基因座单亲PI（PI_（solo））,并推导增加检测的基因座个数（N）的计算公式。结果 Identifiler、PP18D、AGCU EX20、PP21、AGCU EX20＆AGCU 21＋1的R_（VLCPI）分别为24.9%、6.5%、1.4%、0.7%、0.000 1%。在各试剂盒的基因座存在包含关系的前提下,R_（VLCPI）和常染色体基因座数成负相关。PI_（solo）为1.843 2。M_（PI）与PE_（duo）呈显著的正相关（r=0.956,P〈0.001）。增加检测的基因座个数公式为N=「log_（1.843 2）（10 000/P）■。结论本文结果和公式对单亲鉴定案具有一定的应用价值。

英文摘要：

Objective To analyze a large number of Cumulative Paternity Index（CPI） data in Single-parentage identification with stochastic simulation method. Methods Using the software in Identifiler, PP18 D, AGCU EX20, PP21, AGCU 21＋1 system, 1 million groups of STR genotyping of parent-child were analyzed. The average rate of very low CPI（R_（VLCPI））, the median of PI in every loci（M_（PI））, and the average PI of 39 STR loci（PI_（solo）） were counted out. And calculation formula of the number of STR loci that need more testing（N） was derived. Results R_（VLCPI） in Identifiler, PP18 D, AGCU EX20, PP21, AGCU 21＋1 system were 24.9%, 6.5%, 1.4%, 0.7%, 0.000 1%. On the premise of inclusion relations between every kits, the number of autosome STR loci is inversely proportional to R_（VLCPI）. PI_（solo）was 1.843 2. There was a significant positive correlation between M_（PI） and PE_（duo）（r=0.956, P0.001）. The formula of the number of STR loci that need more testing was N= 「 log_（1.843 2）（10 000/P） . Conclusion The result and the formula in this paper are efficient in single-parentage identification.