Objective T o establish a query table of IB S critical value and identification pow er for the detection system s w ith different num bers of ST R loci under different false judgm ent standards. Methods Sam ples of 267 pairs of full siblings and 360 pairs of unrelated individuals w ere collected and 19 auto-som al ST R loci w ere genotyped by G oldeneyeTM 20A system . T he full siblings w ere determ ined using IB S scoring m ethod according to the 'R egulation for biological full sibling testing'. T he critical values and identification pow er for the detection system s w ith different num bers of ST R loci under different false judgm ent standards w ere calculated by theoretical m ethods. Results A ccording to the form al IB S scoring criteria, the identification pow er of full siblings and unrelated individuals w as 0.7640 and the rate of false judgm ent w as 0. T he results of theoretical calculation w ere consistent w ith that of sam ple observation. T he query table of IB S critical value for identification of full sibling detection system s w ith different num bers of ST R loci w as successfully established. Conclusion T he IB S scoring m ethod defined by the regulation has high detection efficiency and low false judgm ent rate, w hich provides a relatively conservative result. T he query table of IB S critical value for identification of full sibling detection sys-tem s w ith different num bers of ST R loci provides an im portant reference data for the result judgm ent of full sibling testing and ow ns a considerable practical value.