  We study the energy levels of graphene magnetic circular quantum dot
surrounded by an infinite graphene sheet in the presence of an electrostatic
potential. We solve Dirac equation to derive the solutions of energy spectrum
associated with different regions composing our system. Using the continuum
model and applying boundary conditions at the interface, we obtain analytical
results for the energy levels. The dependence of the energy levels on the
quantum dot radius, magnetic field and electrostatic potential is analyzed for
the two valleys $K$ and $K'$. We show that the energy levels exhibit
characteristics of interface states and have an energy gap.
