  We investigate the decays of the charmed baryons aiming at the systematic
understanding of hadron internal structures based on the quark model by paying
attention to heavy quark symmetry. We evaluate the decay widths from the one
pion emission for the known excited states, \Lambda_c^*(2595),
\Lambda_c^*(2625), \Lambda_c^*(2765), \Lambda_c^*(2880) and \Lambda_c^*(2940),
as well as for the ground states \Sigma_c(2455) and \Sigma_c^*(2520). The decay
properties of the lower excited charmed baryons are well explained, and several
important predictions for higher excited baryons are given. We find that the
axial-vector type coupling of the pion to the light quarks is essential, which
is expected from chiral symmetry, to reproduce the decay widths especially of
the low lying \Lambda_c^* baryons. We emphasize the importance of the branching
ratios of \Gamma(\Sigma_c^*\pi)/\Gamma(\Sigma_c\pi) for the study of the nature
of higher excited \Lambda_c^* baryons.
