According to the post peak interval characteristics of fiber bundle stretching curve, the new 9 indexes to describe the characteristic are first put forward, i.e. post breaking elongation, post breaking elongation percentage, relative post breaking elongation percentage, post breaking work, post breaking work coefficient, 1/2 post interval load, 1/2 post interval elongation load percentage and post breaking efficiency. And a tentative experiment study is given to the stretching characteristics of ...