Abstarct: Composite Floors are more economical and practical than traditional systems such as block joist system. In order to improvement of condition of composite Floors which have one-way performance, the two-way performance in this study is suggested. By using of governing rules on composite Floors and varied modelings the stress and displacements in two-way system are discussed. By considering tho the comparisons which are done inhere between the one-way and two-way performances of composite floors, it is resulted in that the value of stresses ration and used steel for subsidiary beams are decreased 11.34 and 10.4 perecent, respectively, also the value of frequency is increased 14 percent.therfore the two-way performance is more sufficient structurally and economically than the one-way performance.