Six specimens of abnormal interior joints were tested under reversed cyclic loading. Experimental studies were carried out to investigate the influence of joint core dimensions and axial compression ratio on crack resistance of abnormal joints. The results showed that the crack resistance capacity was mainly provided by the minor core concrete (determined by the top column and the small beam) , and the minor core concrete was in elastic stage before cracks appeared. Furthermore, axial compression ratio was a significant parameter to increase the crack resistance capacity. Based on the test results, a theoretical formula of crack resistance capacity was proposed. The calculated crack resistance capacities of 11 abnormal interior joints were compared with the experimental results, and a good agreement was obtained.