In this paper, we study boundary value problems of nonlinear fractional differential equations in a Banach Space E of the following form: {D-0(p)+x(t) = f(1)(t,x(t),y(t)), t is an element of J = [0, 1], D-0(q)+y(t) = f(2)(t,x(t),y(t)), t is an element of J = [0, 1], x(0) + lambda(1)x(1) = g(1)(x,y), y(0) + lambda(2)y(1) = g(2)(x,y), where D0+ denotes the Caputo fractional derivative, 0 < p, q <= 1. Some new results on the solutions are obtained, by the concept of measures of noncompactness and the fixed point theorem of Monch type.

Caputo fractional derivative; nonlinear fractional differential equations; measures of noncompactness

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