Pre-cast beam-slab is made of pre-cast reinforced concrete beam together with hollow blocks.rnThe pre-cast beams are spaced at certain intervals and the hollow blocks are placed on themrnto form a working platform with out the use of formwork. The slab HCB, hanging betweenrnthe pre cast beams are functioning like a formwork. They give only a temporary supportrnduring the installation phase. Only the pre-cast beams and the slab concrete are load bearingrnparts of the slab.rnIn our country pre-cast beam-slab system is not widely used for construction of mostrnbuildings. The conventional cast institu constructions require lots of formwork andrnconstruction time, which increase the total cost of a project. When pre-cast beam slabrnsystems are introduced in the construction of buildings, an economical construction could bernachieved.rnIn the present study, two types of pre-cast beam elements are chosen. Experimental studiesrnare made on these beam elements by casting them in the laboratory condition. Fromrnexperimental observation, there tried to come up with a new theoretical model. Loaddeflectionrndata was taken from the experiment and compared with the theoretical output.rnFurthermore cost comparison is made between the two systems of slab construction. For thernarrangement of panels used to compare cost, the pre-cast beam-slab system of construction isrnmore economical than the conventional system. Finally, the model gives a hint for futurernstudy in trying to simulate the actual pre-cast beam slab system.