  With the diquark structure of Lambda_c, we investigate the branching ratios
of Lambda_c -> n pi^+ and p pi^0. The results show that without considering the
final state interaction (FSI), the branching ration of Lambda_c -> p pi^+ is
only of order 10^{-6} whereas taking into account the FSI effects, this ratio
could reach 10^{-4} and is at the same order as Lambda_c -> n pi^0. Concrete
values depend on phenomenological parameters adopted in the calculations. These
branching ratios can be measured in the experiments to come.
