Self- compacting concrete (SCC) has characteristics of good flow-ability, non-vibrating and self-compacting. It is the optimum to be used in concrete members with densely distributed steel bar and concrete is inconvenient to be vibrated. The mixture ratio of design grade of C20 and C40 SCC commonly used in project is given after trial mix. The compression stress-strain relation of SCC prism is obtained by MTS. The Mechanical property indexes of SCC are got. The ultimate compression strain of the extreme fiber is acquired by testing beam made of SCC, and the relation between the ultimate compression strain of the extreme fiber in flexural member and the strain at the peak of the stress-strain curve subjected to uniaxial compression is given.