  We propose to study the flavor properties of the top quark at the future
Circular Electron Positron Collider (CEPC) in China. We systematically consider
the full set of 56 real parameters that characterize the flavor-changing
neutral interactions of the top quark, which can be tested at CEPC in the
single top production channel. Compared with the current bounds from the LEP2
data and the projected limits at the high-luminosity LHC, we find that CEPC
could improve the limits of the four-fermion flavor-changing coefficients by
one to two orders of magnitude, and would also provide similar sensitivity for
the two-fermion flavor-changing coefficients. Overall, CEPC could explore a
large fraction of currently allowed parameter space that will not be covered by
the LHC upgrade. We show that the $c$-jet tagging capacity at CEPC could
further improve its sensitivity to top-charm flavor-changing couplings. If a
signal is observed, the kinematic distribution as well as the $c$-jet tagging
could be exploited to pinpoint the various flavor-changing couplings, providing
valuable information about the flavor properties of the top quark.
