Experimental observations and measurements on strength and failure behavior of rock-concrete bi materials are important to correctly understand the response of concrete structure-rock foundation. In this context, a large number of experimental investigations have been carried out in order to identify the interaction at rock-concrete interface, but the influence of inclined interface on strength and failure behavior has not been addressed by adequate experimental studies. The main objective of this investigation is to experimentally investigate the response of the rock-concrete interface at different inclination angles. The effect of inclined interface on strength and failure behavior of rock-concrete bi specimens were investigated under uniaxial compression (UCS), splitting tensile (ST) and point loading (PLS). The variation in strength and failure patterns with respect to the inclination angles of rock-concrete interface were generally observed in all test conditions. The measured strengths and observed failure behaviors during the UCS test were compared with those obtained from ST and PLS tests. It was found that the relation between PLS and interface inclination angle is remarkable in so far as in the case ST conditions in which tensile strength vary as a function of inclination angle. However, these both indirect tests does not provide satisfactory results in determination of the strength variation of specimens when inclination angle of weakness interface starts to become parallel to the loading direction.