We investigate the vortex and trapped states of a microcavity-polariton condensate in a harmonic trap under non-resonant excitation. The stationary states of the microcavity-polariton condensate are obtained from the complex Gross-Pitaevskii equation numerically. From the excitations of vortices and trapped states, the boundaries separating stable and unstable states are plotted in the phase diagram shown by pump powers versus pump-spot sizes. Our analysis provides physical parameters for experiments of creating stable vortices and trapped states in a trapped microcavity-polariton condensate. (C) 2016 Elsevier B.V. All rights reserved.