Weak reproductive traits such as increased calving interval, involuntary culling of dairy cows becuse of reproductive problems, cow replacement costs and loss of milk production will reduce the economic efficiency of industrial dairy farms. In the past decades, higher milk production has always received the most attention among the traits studied in the breeding programs worldwide. However due to the negative genetic relationship between the reproductive traits and productive traits, it leads to reduced reproductive performance of dairy cattels. It is therefore necessary to include the reproductive traits in the breeding programs. Accordingly, a research was carried out to investigate the phenotypic relationship between production traits and reproductive traits based on Isfahan Vahdat cooperative data including 5682056 milk production records as well as 440753 reproductive records that were collected from 89 dairy herds during 1987 to 2017. Then, the corrected milk yield for fat and energy were calculated and fitted to the Wood function curve for each animal. In this study, the phenotypic correlation between traits ranging from 0.005 for milk 305 with peak time (corrected for energy) and 0.009 for milk 305 with incremental slope to -0.965 for descending slope with lactation persistency and -0.815 for milk yield on the first day with incremental slope. Also, the phenotypic correlation of productive and reproductive traits ranged from 0.002 for incremental slope with stillbirth and 0.003 for milk production at peak time with age at first calving to -0.526 for lactation persistency with dry period and 0.525 for the dry period with peak time. Phenotypic correlation between calving interval with dry period was 0.000, twin birth with age at first calving -0.002 and lactation with calf sex -0.002 open days with calving interval 0.902 and 0.902. The number of insemination with open days was estimated to be 0.779 (p 0.0001). In this study, the duration of dry period and open days as manageable traits showed the highest correlation with other traits including productive and reproductive traits. Key Words: Milk yield curve, Reproductive traits, Phenotypic correlation, Incomplete gamma function