  It is shown that the generalized (with nonpolynomial Lagrangian) Chern-Simons
membranes and in general $p$-branes moving in $D$-dimensional target space
admit an infinite set of secondary constraints. With respect to the Poisson
bracket these constraints satisfy closed algebra containing $p$-dimensional
classical $W$ algebra as a subalgebra. In the case when the target space
dimension $D$ is finite the theory is topological.
