Abstract: Objective A case of half sibling was determined with multiple genetic markers, which could be potentially applied for determination of half sibling relationship from same father. Methods Half sibling relationship was detected by 39 autosomal STR genetic markers, 23 Y-chromosomal STR genetic markers and 12 X-chromosomal STR genetic markers among ZHAO-1, ZHAO-2, ZHAO-3, ZHAO-4, and ZHAO-5. Results According to autosomal STR, Y-STR and X-STR genotyping results, it was determined that ZHAO-4 （alleged half sibling） was unrelated with ZHAO-1 and ZHAO-2; however, ZHAO-3 （alleged half sibling）, ZHAO-5 （alleged half sibling） shared same genetic profile with ZHAO-1, and ZHAO-2 from same father. Conclusion It is reliable to use multiple genetic markers and family gene reconstruction to determine half sibling relationship from same father, but it is difficult to determination by calculating half sibling index with ITO and discriminant functions.

Key words: forensic genetics, parent-child relations, sibling relations, short tandem repeat sequences