  A superfield formulation is presented of the central charge anomaly in
quantum corrections to solitons in two-dimensional theories with N=1
supersymmetry. Extensive use is made of the superfield supercurrent, that
places the supercurrent J^{mu}_{alpha}, energy-momentum tensor Theta^{mu nu}
and topological current zeta^{mu} in a supermultiplet, to study the structure
of supersymmetry and related superconformal symmetry in the presence of
solitons. It is shown that the supermultiplet structure of (J^{mu}_{alpha},
Theta^{mu nu}, zeta^{mu}) is kept exact while the topological current
zeta^{\mu} acquires a quantum modification through the superconformal anomaly.
In addition, the one-loop superfield effective action is explicitly constructed
to verify the BPS saturation of the soliton spectrum as well as the effect of
the anomaly.
