|These days, the Composite Slabs with Deep Deck plate was commonly used in domestic construction site, and, the application of the Slim Floor system was increased from the Enlargement and High-rise Building. But, Slim Floor system using the Deep Deck was shown safety problem caused by the deflection and local buckling in construction phase when used to more than 6m. Therefore, for solving the problem, the installation of the shores is essential. This study is realize the long span slab without shores from control the deflection through applied the pre-tensioning elements in CAP deck. In addition, by applying the pre-tensioning member as the tensile member of the CAP Deck slab, the pre-tensioning member for the shores tries to be used as the structural member. Accordingly, to determine the flexural performance of the CAP Deck slab through the pre-tensioning force in tensile member, and, the composite effect of the CAP Deck slab by the experiments.