Abstract : This paper presents a new concept for a lightweight GFRP slab. The slab construction consists of two layers: a glass fiber-reinforced (GFRP) sections and lightweight concrete (LC). Mechanical tests on six slabs were performed with three parameters the spacing between the GFRP sections, The geometry of GFRP cross section and the stiffeners. Increasing the spacing between GFRP sections reduced the ultimate load capacity of the slab by Increasing the spacing from 233 to 350 lead to reduce the ultimate load from 112 to 91.5 KN. In addition to the different geometry and cross section area led to different inertia, Although the same amount of glass fiber and same volume of specimens the ultimate load arranged in descending order due to the inertia of GFRP sections. The results of using glass fiber stiffeners between GFRP sections were not meet the expectation it had a little bit effect on the ultimate load capacity. It leads to increase in slab ultimate load capacity by 3%. However, the slab failure started by flexural cracks then slippage between the GFRP and the LC. The experimental results compared to theoretical results from previous models and it showed a positive result with HUGO model [1] with matching ratio from 80 to 100%.