The gene encoding regulatory subunit 15 A of protein phosphatase 1 produces a protein that is a universally present protein phosphatase in eukaryotic cells.In this study,genomic DNAs were extracted from the blood of 89 Chinese Holstein cows and were used as templates for PCR amplification of the target fragment of the PPP1R15A gene.The product was tested and a polymor-phic site,E3-250T＞A was found.The polymorphism of this side and its correlation with milk pro-duction traits in Chinese Holstein cattle were statistically analyzed using SPSS 23.0 software.The findings revealed three genotypes at this site:AA,AT and TT.Cows possessing the AT and TT genotypes exhibited significant differences(P＜0.01)in milk fat and solid non-fat content com-pared to those with the AA genotype.While no significant differences were noted for other milk production traits,including milk yield,protein,lactose,somatic cell count,blood urea nitrogen,and corrected milk.The identification of functional SNPs in the PPP1R15A gene provides a theoretical basis for further research and identification of causal variations in the cow PPP1R15A gene.