Abstract: Based on the experimental results for concrete filled steel tube columns subjected to compressson, flexure and shearing, for differentshear span ratio, the transfer mechanism and the failure modes, the interaction between the steel tube and the concrete, a series formulas for evaluating the strength of the concrete filled steel tube column have been established by using the wedge theory and plasticity.It is found that the oftairred results by the presenting formulas are in good agreement with the experimental results these formulas are simple and suitable for engineering application.