  Currently, the fifteen new periodic solutions of Newtonian three-body problem
with equal mass were reported by \v{S}uvakov and Dmitra\v{s}inovi\'{c} (PRL,
2013) [1]. However, using a reliable numerical approach (namely the Clean
Numerical Simulation, CNS) that is based on the arbitrary-order Taylor series
method and data in arbitrary-digit precision, it is found that at least seven
of them greatly depart from the periodic orbits after a long enough interval of
time. Therefore, the reported initial conditions of at least seven of the
fifteen orbits reported by \v{S}uvakov and Dmitra\v{s}inovi\'{c} [1] are not
accurate enough to predict periodic orbits. Besides, it is found that these
seven orbits are unstable.
