Resin-bonded fixed partial dentures (F.P.D) can be used for conservative treatment of partially edentulous patients. There are numerous studies regarding the strength of resin composite bond to base meta! alloys. Shear bond strength of three resin systems were invistigated. In this study these systems consisted of: Panavia Ex, Mirage FLC and Marathon V. Thirty base metal specimens were prepared from rexillium III alloy and divided into three groups. Then each group was bonded to enamel of human extracted molar teeth with these systems. All of specimens were stored in water at 37ac for 48 hours. A shear force was applied to each specimen by the instron universal testing machine. A statistical evaluation of the data using one-way analysis of variance showed that there was highly significant difference (P<0.01)between the bond strengths of these three groups.The base metal specimens bonded with panavia Ex luting agent, exhibited the highest mean bond strength. Shear bond strength of the specimens bonded to enamel with Mirage F1C showed lower bond strenght than panavia EX. However, the lowest bond strength was obtained by the specimens bonded with Marathon V.