  Virasoro constraint is the operator algebra version of one-loop equation for
a Hermitian one-matrix model, and it plays an important role in solving the
model. We construct the realization of the Virasoro constraint from the
Conformal Field Theory (CFT) method. From multi-loop equations of the
one-matrix model, we get a more general constraint. It can be expressed in
terms of the operator algebras, which is the Virasoro subalgebra with extra
parameters. In this sense, we named as generalized Virasoro constraint. We
enlarge this algebra with central extension, this is a new kind of algebra, and
the usual Virasoro algebra is its subalgebra. And we give a bosonic realization
of its subalgebra.
