Combined with the results of flexural toughness experiments on 16 groups of steel fiber reinforced concrete(SFRC) specimens, both advantages and disadvantages of the flexural toughness tests and evaluation methods commonly used in design guidelines in China and abroad were discussed, and a new evaluation method for flexural toughness of SFRC, which was more suitable for structural evaluation in the practical engineering, was proposed. On the basis of this method, the influences of steel fiber volume fraction on flexural toughness of concrete(C30) and high strength concrete(C50) were studied. The results show that the new evaluation method given in this paper, which is simple and practical, can overcome the deficiencies of current evaluation methods, and can be used as a reference in revising the contents of the China technical specification for steel fiber reinforced concrete structures.