This paper presents the investigation of flexural behaviour of a two way bending on Geo Polymer Concrete slab with simply supported edge conditions. The size of the slab panel adopted is 1m x 1m x 0.05 m. By using yield line theory, the moment of resistance and yield line patterns are predicted and the corresponding theoretical deflections is also computed. Reinforcement details of these slabs are calculated using the ultimate load method as per IS: 456-1978 code provisions. The materials used for the preparation of GPC are regular conventional aggregate materials, flyash, NaOH of 8 Molarity solution using a mix proportion 1:1.74:3.097 and the ratio of alkaline liquid to flyash is 0.45. The mechanical properties like compressive strength, split tensile strength and flexural strengths of GPC are determined. The slab elements are tested with UDL under bending of the loading frame of capacity 1000 kN. The compressive strength of GPC is 28.1 MPa after 28 days of ambient curing. A 6 mm diameter bar with 120 mm spacing of Fe250 grade steel is used as the main reinforcement for casting of slabs. After testing, the test results of experimental bending moments, deflections and crack patterns on tension side are compared to the theoretical values which are computed from Yield line theory.