| This paper deals with the existence of positive solution for Dirichlet-Neumann type boundary value problems of nonlinear fractional differential equations. First, it solves the Green function for boundary value problems and researches the positive property of the Green function. Next, it solves the sufficient condition which is used to certify the existence of positive solution for Dirichlet-Neumann type boundary value problems of nonlinear fractional differential equations with the fixed point theorem in cones. At last, a typical example is given to explain the conclusion we derived in this paper. |