Résumé
30 chorinic villi in early pregnancy (8-10 weeks)and their parent blood samples were analysedusing the method of restriction fragment length polymorphisms with single locus DNA probes of PAC255 and PAC256. Based on the gene frequencies of these two loci in Chinese and the relativechance of obligatory gene in each triplet, the cumulative parternity index and cumulative relativechance of paternity were calculated. The range of the former is 56. 80- 8333. 50, and the later is 98.27 - 99. 99 %. According to the international standard of paternity test, in the 30 pedigrees, 20 cases(66. 7 % )were assured for their paternity. It is showed that the combination of PAC255 and PAC256single locus DNA probes for the paternity test of early pregnancy is very available.