Optimal reproductive performance of dairy cows formed the basis of economic herd lifetime. Success or failure in each insemination, as a practical measurement of cow fertility has been selected and considered as conception rate. Evaluation of factors affecting fertility in cows and heifers identified them as much as possible, which improve management and mating programs. In the present study linear and threshold animal models was used to estimate (co) variance components, heritability, genetic and phenotypic correlations for production and reproduction traits related to conception rate in Isfahan Holstein dairy cows. The traits were included: age at first service (AFS), days to first service (DFS), conception rate (CR), insemination number per service (INS), success to first insemination (SF), open days (OD), calving interval (CI), days in milk (DIM), milk yield over 305-d lactation (MY). Because, the conception rate in heifers and cows are different and also there are several limitations in reproductive traits, therefore heifers and cows were analyzed separately. Also, when conception accrues in heifers there is no production, therefore the correlation between production traits and conception rate was analyzed only in cows. A total number of 83540 records from first parity during 1981 to 2010 and a total number of 170172 records in parity 2 to 6 during 1978 to 2008 were analyzed (All data were collected from Vahdat Industrial Agriculturists and Dairymen Cooperative). The fixed variables with significant effect on these traits were identified. Bivariate linear models based on Restricted Maximum Likelihood (REML) method were considered to estimate genetic parameters. As expected, estimated heritabilities for reproductive traits were low (below 0.1). The lowest and highest heritability of traits were related to SF (0.019 ± 0.004) and INS (0.048 ± 0.004) in heifers and SF (0.022 ± 0.005) and OD (0.076 ± 0.003) in cows respectively. The estimated heritabilities were higher in continues traits (OD, CI) than categorical and binary traits (INS and SF). The heritabilities for production traits were higher than reproduction traits, (0.266 ± 0.051) and (0.166 ± 0.043) for MY and DIM respectively. Strong genetic correlations were estimated between conception rate and fertility traits .The maximum value of these coralations was related to SF, that was estimated about (0.999 ± 0.007) for heifers and (0.974 ± 0.009) for cows, that shows these traits have the same genetic factors and can replace each other in fertility index. Genetic correlation between conception rate and production traits were estimated (-0.688 ± 0.050) for MY and (-0.308 ± 0.059) for DIM that showed the antagonistic correlation between these traits. This study indicated that, conception rate has a significant correlation with other fertility traits and highly affected by production traits. Therefore to improve conception rate and reproductive performance, fertility and production traits should be combined in selection index for breeding programs. Keywords: Genetic parameters, Conception rate, Reproductive performance, Animal model, Holstein dairy cows