  We study quasi-finite representation of the $\Winf$ algebra recently proposed
by Kac and Radul. When the central charge is integer, we show that they are
represented by free fermions and bosonic ghosts. There are some nontrivial
representations with vanishing central charge. We discuss that they may be
described by large $N$ limit of topological models. We calculate their operator
algebras explicitly.

High Energy Physics - Theory