  We study phase structure of the moduli space of a D0-brane on the orbifold
C^3/Z_2 \times Z_2 based on stability of quiver representations. It is known
from an analysis using toric geometry that this model has multiple phases
connected by flop transitions. By comparing the results of the two methods, we
obtain a correspondence between quiver representations and geometry of toric
resolutions of the orbifold. It is shown that a redundancy of coordinates
arising in the toric description of the D-brane moduli space, which is a key
ingredient of disappearance of non-geometric phases, is understood from the
monodromy around the orbifold point. We also discuss why only geometric phases
appear from the viewpoint of stability of D0-branes.
