Steel deck composite slabs are widely used for composite floor systems. In this slab, steel deck remains permanently in place as an integral part of the floor system, and the hardened concrete slab acts compositely with the profiled steel deck. Composite slabs lead to a notable reduction in the structure weight, the construction cost, time and have enough strength. Steel decks perform two functions: they act as formwork while concreting is done and as tension reinforcement bars. The concrete, distributes loads and protect the steel deck from fire. In this study, two composite frames with and without steel deck were modeled using the finite element software, ABAQUS and nonlinear dynamic analysis was done and their seismic behavior such as period, lateral displacement, base shear, plastic energy dissipation of the frames and crack formation procedure in concrete slab were investigated. Results showed that using steel deck in composite slab, reduced period and maximum lateral displacement of the frame but base shear and plastic energy dissipation of frames increased .Also plastic hinge formation procedure of two frames was the same.