It is calculation of non - metallic reinforced concrete beams. Beams are reinforced with Fiber Reinforcement Polymer. Reinforced bars putted only in tension zone. There is view of three methods of calculation, witch grounded on method of “Moment – Curvature” worked out by CEB-FIP and it has predicted by FRP reinforced concrete beams. Deflections are calculated with Bilinear method, Mean Moment of Inertia and the method formulated by Benmokrane’s and compared with Eurocode EN 1992-1-1:2004. Experimental results have taken from experiments of other authors. There is defined, how much amount of reinforcement and elastic module of concrete affect deflections and compress stress in concrete. Coefficient with depicts the bond quality of bars have to specify. It is suggested to accept the value 1,0. Acquired results show that theoretically calculated deflections are lesser than experimentally determined. Consequently coefficient of concrete and fiber collaboration has to be decreasing at reinforcement of this form.