  Matrix models of 2D quantum gravity are either exactly solvable for matter of
central charge $ c\leq 1, $ or not understood. It would be useful to devise an
approximate scheme which would be reasonable for the known cases and could be
carried to the unsolved cases in order to achieve at least a qualitative
understanding of the properties of the models. The double scaling limit is an
indication that a change of the length scale induces a flow in the parameters
of the theory, the size of the matrix and the coupling constants for matrix
models, at constant long distances physics. We construct here these
renormalization group equations at lowest orders in various cases to check that
we reproduce qualitatively the properties of $ c\leq 1 $ models.
