According to the constitutive relation built based on the uniaxial tensile and compression tests of ECC, we proposed the calculation theory of flexural capacity of cross section of CFRP-ECC based on plain cross-section assumption. According to the result of four-point bending test, we proved the validity of calculation theory by comparing and analyzing the result of calculation theory and test. The comparison show that result of the calculation theory of flexural capacity of cross section and test agrees well, and the maximum error is under 4%.This research result can provide reference for the structural calculation of non-metallic reinforced high toughness cementitious composites. Introduction How to increase the deformation and improve the brittleness of concrete, and these problems has caused the attention of the scholars both at home and abroad. Engineered Cementitious Composites [1-3] ,which is a short fiber reinforced cement based on fracture mechanics, microscopic physical mechanics and statistical optimization design. The fiber volume is not more than 2.5% of the total volume, and has strain hardening and fracture characteristics under tensile load. The stable tensile strain can reach above 3%,and material specimen shows that the maximum crack width can be controlled within 100 microns .Due to the material toughness and good durability can solve the above problems, both at home and abroad have been applied in practical engineering, such as the Hong Kong-Zhuhai-Macao bridge in our country and Japan yokohama, building, etc. Traditional reinforced concrete structures are easily to cause the loss of bearing capacity and eventually led to the problem of poor durability, because cracking in the process of use within the vulnerable to environmental impact and corrosion of reinforcement. In order to solve this problem, experts and scholars try using high-performance materials instead of steel so as to improve the structure durability. CFRP [4] is a high performance carbon fiber composite material composed of carbon fiber and matrix .It has light weight, high strength, corrosion resistance, fatigue resistance and other advantages. It is better to solve the problem of the durability of steel caused by corrosion instead of steel in concrete members. There is significant difference between reinforced concrete and CFRP-ECC materials in constitutive relation and ordinary reinforced concrete normal section flexural analysis theory is not applicable. Based on ECC uniaxial tensile and compressive constitutive relation, and combination of CFRP tensile stress-strain relationship, we put forward the normal section flexural bearing capacity calculation theory suitable for CFRP-ECC structure. At the same time, from the four-point bending test of CFRP-ECC specimen, we are trying to prove the correctness of the computational theory through the comparison and analysis. 2nd Annual International Conference on Advanced Material Engineering (AME 2016) © 2016. The authors Published by Atlantis Press 113 The Analysis Theory of Flexural Capacity of Cross Section The Constitutive Relation of ECC Based on the obtained experimental data of uniaxial tension and compression experiments of ECC specimens, fitting the stress-strain curve and the constitutive relations are as follows: 0 1 2 3 4 5 6 7 8 0 1 2 3 4 (to,to) (tp,tp) 3 2 (%) Fitted Curve 1 ( M P a )