Electronic Journal of Differential Equations, Vol. 2010(2010), No. 147, pp. 1-11. Title: Solutions of fractional diffusion problems Author: Rabha W. Ibrahim (UKM, Malaysia) Abstract: Using the concept of majorant functions, we prove the existence and uniqueness of holomorphic solutions to nonlinear fractional diffusion problems. The analytic continuation of these solutions is studied and the singularity for two cases are posed. Submitted April 20, 2010. Published October 18, 2010. Math Subject Classifications: 34A12. Key Words: Fractional calculus; majorant function; diffusion problems; holomorphic solution; Riemann-Liouville operators.