This study was conducted to determine the genetic correlation between age at first calving and some productive (milk yield, milk fat yield and percent) and reproductive (open days, dry period and calving interval) traits. The data were used in this study include 534857 records of productive traits and 475589 records of reproductive traits in 3 first lactation of Isfahanian Holstein dairy cows. The DFREML software package was used to analysis data set. To estimate genetic and phenotypic parameters the SIMPLEX method and No.7 th animal model were used for univariate and multivariate analyse respectively. The average and heritability of age at first calving were calculated to be 26.57 and 0.55 respectively. The heritability of milk yield, milk fat yield and fat percent in difference lactation period, were 0.11- 0.15, 0.13 – 0.21 and 0.17 – 0.25 respectively. The heritability of maternal effects and fix environmental effects was calculated in univariate analysis. The genetic correlations of productive traits in different lactation period exhibited reductional trend. The genetic correlation between age at first calving and milk yield, milk fat yield, fat percentage, open days, calving interval and dry period in second lactation period were calculated to be 0.19, 0.13, 0.16, 0.11, 0.056 and 0.043 respectively, however these correlations in third lactation period had almost reductional trend. All calculated correlations between age at first calving and other studied traits had significant differences in all 3 lactation period (P 0.05). Because of positive genetic correlations with productive traits, age at first calving could affect animal productive performance.