Abstract: Objective: To explore the association of polymorphisms in calcineurin genes with elite endurance athlete performance.Methods: This paper compared genotypic/allelic frequencies in 55 single nucleotide polymorphisms (SNPs) of the five genes (PPP3CA, PPP3CB, PPP3CC, PPP3R1 and PPP3R2) encoding the calcineurin protein subunits between 123 elite runners (cases, n=61 women) and 125 healthy non-athletes (controls, n=56 women) from the same ethnic background (Hans Chinese) , and used the dual-luciferase reporter assay to analyse the functional significance of the associated SNPs.Results: The C allele of the PPP3CA rs3804358 polymorphism was overrepresented in athletes (17%) compared with controls (8%) (P=0.003) , whereas the T allele of the PPP3CB rs3763679 polymorphism was underrepresented in athletes (23%) compared with controls (37%) (P=0.001) .The luciferase reporter constructs containing C allele of the rs3804358 and rs3763679 polymorphisms produced significantly greater luciferase activity than that of the G or T alleles respectively.Conclusion: The findings suggest that rs3804358 and rs3763679 polymorphisms have functional significance and show evidence of association with elite endurance performance.