The main purpose of this study were to estimate the economic values of milk, fat and protein yield. Therefore, simple models describing the production and management status of dairy cow farms were presented in Iran. Economic value estimates were produced by the simulation of production systems (i.e. milk, fat and protein) and also by the simulation of dairy cow nutrition requirements using CNCPS. Economic value were estimated during four milking stages (stage 1: from day one to 20, stage 2: from day 21 to 80, stage 3: from day 81 to 200 and stage 4: from day 201 to 305) and at three nutrition cost levels (maximum, medium and minimum nutrition costs). The economic values of milk production at different nutrition cost levels during stage 1 ,2,3 and 4 were estimated as follows: the minimum nutrition cost level were 2254.3, 4687.9, 3799.2 and 2766.3 Rials respectively; the maximum nutrition cost level were 1076.2, 3394, 2290.2 and 713.9 Rial respectively; the medium nutrition cost level were 1682.6, 4029.1, 2997.1 and 1715 Rials respectively. The economic value of fat production at different nutrition cost levels during stages 1,2,3 and 4 were estimated as follows: the minimum nutrition cost level were 90368, 109974, 108996 and 105985 Rials respectively; the maximum nutrition cost level were 76751, 92265, 76884 and 60336 Rials respectively; the medium nutrition cost level were 81794, 102543, 95870 and 86459 Rials respectively. The economic value of protein production at different nutrition cost levels during stages 1 ,2,3 and 4 were estimated as follows: the minimum nutrition cost level were -36983, -52073, -37580 and -24843 Rials respectively; the maximum nutrition cost level were -87464, -86613, -95779 and -101988 Rials respectively; the medium nutrition cost level were -51928, -69479, -71255 and -63113 Rials respectively. The Negative economic value of protein production is due to ignoring the production reward in milk pricing system Keywords: Economic value, production traits, breeding goals, random regression, sub-index economic