Abstract: The main failure modes of interior connection in RC slab_column are punching shear and flexural failure. Combining with the tests at home and abroad, the punching shear bearing capacity calculating formula of interior connection given by Code for Design of Concrete Stmctures(GB50010-2002)is verified. According to the calculating width of equivalent beam subjected to earthquake action that received by elastic analysis, the flexural beating capacity calculating formula of interior slab_column connections is proposed. At last, the judgment method for the two failure modes is presented.