Abstract: Objective:To study the association of 5 polymorphisms in EDN1 and NOS2A genes with aerobic training response in order to find genetic markers for predicting aerobic training effect.Methods:A cohort of 102 young men was submitted to an 18-weeks endurance training event.All of the subjects were North Han nationality of China and had no training background.The phenotype parameters of aerobic capacity and cardiac function were measured before and after endurance training.The aerobic capacity indexes including O2max,ventilation aerobic threshold,running economy and respiratory function.The cardiac function was detected under rest and during 3 fixed-loads exercise.Association was observed between the change of phenotype parameters and polymorphisms including SNP/rs5370,rs1800997,rs4714383 in EDN1 gene and STR(CCTTT)n and SNP/rs2248814 in NOS2A gene.Main Results:(1) After training,the increase of sedentary EDD and SV in EDN1 SNP/rs5370 GT genotype was significantly higher than that in GG genotype.The increase of sedentary LVM in EDN1 SNP/rs1800997 3A/3A genotype was significantly higher than that in 3A/4A genotype.(2) The n value of NOS2A STR(CCTTT)n showed significant positive linear correlation with VEmax before training and the increase of VEmax and VT-VE after training.The n value of STR(CCTTT)n also exhibited significant positive linear correlation with EF during fixed-load exercise before training and the increase of SVI and CO during fixed-load exercise after training.Furthermore,the increase of these indexes in n>11 allele carriers was significantly higher than that in double n≤11 alleles carriers.Conclusion:Among men of Han Nationality in North China,the GT and 3A/3A genotypes carriers of SNP/rs5370 and rs1800997 in EDN1 gene can get better improvement of cardiac function from aerobic training than GG and 3A/4A genotypes carriers.The n>11 allele carriers of STR(CCTTT)n in NOS2A gene can get better improvement of cardiopulmonary function from aerobic training than carriers of double n≤11 alleles.