This paper provides the results of the study on the Structural Behavior of the Composite metal deck slab system. In applications, the composite metal deck serves not only as the working platform and the form for the concrete casting, but also as a positive moment resistance and the main tensile reinforcement for slabs. 12 specimens are tested for this paper. Parameters in this study are the depth of topping concrete(80mm, 100mm), the thickness deck plates (1.2mm, 1.6mm) and shear spans(L/7, L/4, L/3). Based on experimental and analytical study, the deflection at mid-span, strength and end slip are developed in this paper. Finally the purpose of this paper is to provide basic knowledge of developing the shape of composite metal deck that is economical and resists larger loads.