Abstract: To research the mechanical property of steel beam and concrete column composite joints with extended end-plate connections,pseudo-static test,low cyclic loading test,was executed on 7 test specimens,all of which were welded compound-ring-hoop concrete column and cellular steel beam composite joints.The experimental results reflected that the load value was smaller when steel beam and concrete column composite joints crack with extended end-plate connections was appearing; after the test specimens yielded, the main X-type crossing incline shear cracks were appearing in areas of joints; when it came to the stage of destroy, continuous seam appeared in areas of joints core, moreover, part of concrete in those areas was crushed and plumped, hoops yielded, stiffness degraded, and test specimens were destroyed; finally, the destroying pattern in aforementioned areas was shear compression failure.Compared with other experimental results, the fastest energy-consuming test specimen were those that with extended end-plate bolted connections,hoops,longitudinal bars and concrete in areas of joints core can fully show their functions.As a result,the extended end-plate bolted connection was a comparatively reasonable pattern of joints.