  Matter collineations (MCs) are the vector fields along which the
energy-momentum tensor remains invariant under the Lie transport. Invariance of
the metric, the Ricci and the Riemann tensors have been studied extensively and
the vectors along which these tensors remain invariant are called Killing
vectors (KVs), Ricci collineations (RCs) and curvature collineations (CCs),
respectively. In this paper plane symmetric static spacetimes have been studied
for their MCs. Explicit form of MCs together with the Lie algebra admitted by
them has been presented. Examples of spacetimes have been constructed for which
MCs have been compared with their RCs and KVs. The comparison shows that
neither of the sets of RCs and MCs contains the other, in general.
