  We consider a gradient flow associated to the mean field equation on $(M,g)$
a compact riemanniann surface without boundary. We prove that this flow exists
for all time. Moreover, letting $G$ be a group of isometry acting on $(M,g)$,
we obtain the convergence of the flow to a solution of the mean field equation
under suitable hypothesis on the orbits of points of $M$ under the action of
$G$.
