Abstract: Objective To establish and evaluate the method of full sibling identification based on the number of allele shared among autosomal STR Loci. Methods Two hundred and eighty full sibling pairs and 2 003 unrelated individual pairs were genotyped in 15 STR loci with Identifiler Kit, and the number of allele shared among the 15 STR loci(S15) and full sibling index(FSI) were calculated. Fisher discriminant functions were established with SAS 8.2 software based on S15, the power of which were compared with ITO method. Results The distribution of S15 in full sibling pair group and unrelated individual pair group were in accord with normal distribution. The established Fisher discriminant functions for each group were ZFS= 3.269 70 S15-31.511 74 and ZUI=1.700 58 S15-8.524 11, respectively. The average error of probability in sibling and unrelated pair group was 0.029 8. There was no statistically significant difference on the power of full sibling discriminant between the method based on the number of allele shared among the 15 STR loci or the CODIS 13 STR loci and the ITO method. Conclusion The method based on the number of allele shared among the 15 STR loci in full sibling identification is convenient, credible, easy to handling and unaffected by the allele frequency of STR loci.

Key words: forensic genetics, sibling relations, alleles, short tandem repeat, discriminant analysis, ITO method