This article reports one case of tri-allele detected in the TPOX locus of a child in duos. The Goldeneye20 A kit was used for detecting. The 3500 DX genetic analyzer was used for electrophoresis and Genemapper genotyping software was used confirm its genotyping(8, 9, 11). When the tri-allelic gene is detected in the paternity test, under the premise of eliminating contamination, at least two kits are required to confirm the test to ensure the reliability of the identification and PI calculation. In order to...