A prediction of construction cost in preparation for construction document is calculated in compliance with the unit cost in Public construction of korea. This eventually means that the reasonable construction cost of a building can't be determined before construction document phase cost of construction is settled and that the cost of construction is calculated inefficiently because of connection failing between cost management of detailed estimation and information. To improve those problems, therefore, Cost estimating model of structural building elements with approximate quantity survey method is suggested in this research. The model predict the amount of materials and the cost of construction on the basis of historical similar cases. In the direction of data analysis of this research, ratio statistics value is put to practical use to fit into the peculiarities of approximate estimate of each work trade on the basis of actual data amount of materials of historical cases. In addition, the construction phase is connected through the result of a approximate estimate sorted by elements, details work trade.