Abstract: The Probability of discrimination (DP)and of paternity exclusion (PE)in Chinese Han nationalities has been calculated with 20 genetic markers. We divided these systems into four kinds depending on its probabilities of discrimination. we discussed the application problems of DP and pc (probabilities of coincidence) in the practice of forensic serology and pointed out the way for further enhance PE in Chinese. A computer programs are also destribed, which can be used for calcuation of PE with HLA systems.