We study a three-dimensional symmetric Chern-Simons field theory with a general covariance, and the original Chern-Simons theory turns out to be just a gauge fixed action of the symmetric Chern-Simons theory whose constraint algebra belongs to a fully first-class-constraint system. Finally, we shall discuss some connections between the present symmetric formulation of the Chern-Simons theory and the Stukelberg mechanism.