In this paper, we developed a crack width measurement program by image analysis and carried out an actual size loading experiment of RC nonstructural wall with parameters of rebar interval and rebar ratio. As a result, it was found that the width and the slip on the cracks increased with the increase of the reinforcing bar interval, and there was no effect on the crack width due to the difference in the reinforcing bar ratio. Moreover, the crack width density distribution and the slip were measured by an image analysis.
