This study was conducted to investigate the factors influencing retained placental, its genetic and phenotypic relationshi among retained placental with reproductive traits in dairy cattle in Isfahan province. To do so, 191251 records of 37,736 dairy cows from parity 1 to 6 during 1988 -2017 were analyzed wich have been collcted from Vahdat Industrial agriculturists and Dirymen Cooperative. The factors affecting on retained placenta analyzed using LOGISTIC procedure of SAS. Results showed that the factors such as herd-year-season of calving,parity, dystocia, calf sex, birth-calf weight,gestation lenth and towining.Genetic and phenotypic parameters were estimated using DMU software Single trait and tow trait by animal models based on restricted maximum likelihood(REMEL) using DMU software. The heritability of reproductive traits was estimated to be less than 0.1. The heritability of the retained placenta was estimated to be 0.07. Estimated correlations between retained placenta with reproductive traits such as the days to first services, number of insiminatin per pregnancy, and open days from first to sixth calving were (0.01 to 0.3), (0.1 to 0.1) and (-0.2 to -0.04), respectively, these values are in the weak to medium range, which may be indicative of the contribution of the variance of non-genetic additive or the residual factors to the occurrence of this disorder. The calculated genetic and phenotypic trends were respectively for retained placenta (-0.02 and -0.2), days to first services (0.001 and 0.08), number of inseminatio per pregnancy (-0.0001 and 0.08). ) And for open days (-0.07 and 0/380). The findings showed that the heritability and correlation of the retained placenta is low and close to zero and the retained placenta is more affected by environmental factors, so it can be prevented by controlling environmental factors to a large extent. Although genetic trends indicate that although retained placenta are one of the major postpartum disorders, ut in period of study have not breeding programs and have not been attempted to improve environmental conditions. Keywords : Retention placenta, Genetic and phenotypic analysis, Reproductive performance, Holstein cattle.