We derive a reconstruction procedure of the potential from the scatter
ing matrix of the 3-dimensional Dirac operator by using the method of
Faddeev for the multi-dimensional inverse scattering theory for Schrod
inger operators. We consider two problems in almost the same framework
s: the reconstruction of slowly decreasing potentials from the scatter
ing matrices for all high energies and that of exponentially decreasin
g potentials from the scattering matrix for a fixed energy.