The objective of this paper was to clarify the influence of mixed-mode loading conditions on the load-defomation relationships and the crack propagation of notced concrete beam specimen. Mixed-mode loading conditions were made by changing the distance from the loading line to the notch line of the specimen. Crack propagation of the specimen was observed and it was compared with the result of analysis which was based on the linear elastic fracture mechanics (LEFM). According to the results, it was clarified that the crack propagating direction from the notch tip was nearly straight for the various mixed-mode conditions, and it could be assumed by the analysis of LEFM. In case which the mode II factor was increasing, the stiffness ; the maximum load ; the crack sliding displacement ; were increased, and the unstable fracture was occured.
