Electronic Journal of Differential Equations, Vol. 2012 (2012), No. 208, pp. 1-11. Title: Existence of positive solutions for nonlinear fractional systems in bounded domains Author: Imed Bachar (King Saud Univ., Riyadh, Saudi Arabia) Abstract: We prove the existence of positive continuous solutions to the nonlinear fractional system $$\displaylines{ (-\Delta|_D) ^{\alpha/2}u+\lambda g(.,v) =0, \cr (-\Delta|_D) ^{\alpha/2}v+\mu f(.,u) =0, }$$ in a bounded $C^{1,1}$-domain $D$ in $\mathbb{R}^n$ $(n\geq 3)$, subject to Dirichlet conditions, where $0<\alpha \leq 2$, $\lambda $ and $\mu $ are nonnegative parameters. The functions f and g are nonnegative continuous monotone with respect to the second variable and satisfying certain hypotheses related to the Kato class. Submitted September 8, 2012. Published November 25, 2012. Math Subject Classifications: 35J60, 34B27, 35B44. Key Words: Fractional nonlinear systems; Green function; positive solutions; blow-up solutions