A systemically study on the new space structure steel - concrete composite ribbed shell is made, which is loaded by stepped load. The ultimate bearing capacity and failure modes are investigated based on the characteristic response indicators. In the foundation of large number of parameters analysis, the influence of the span ratio, span, boundary conditions and initial imperfection on the ultimate bearing capacity and instable dynamic failure are discussed in details. All the results will provide mass of data to the investigation of failure mechanism and the property under complex dynamical loads.
