  We show that supersymmetry can be broken mainly by hidden matter condensates
in the observable matter direction in generic superstring models. This happens
only when the fields whose VEVs give masses to hidden matter do not decouple at
the condensation scale. We find how the parameters of the string model and the
vacuum determine whether supersymmetry is broken mainly by hidden matter or
gaugino condensates and in the matter or moduli directions.
