  The derivation of accurate stellar populations of galaxies is a non-trivial
task because of the well-known age-metallicity degeneracy. We aim to break this
degeneracy by invoking a chemical evolution model(CEM) for isolated disk
galaxy, where its metallicity enrichment history(MEH) is modelled to be tightly
linked to its star formation history(SFH). Our CEM has been successfully tested
on several local group dwarf galaxies whose SFHs and MEHs have been both
independently measured from deep color-magnitude diagrams of individual stars.
By introducing the CEM into the stellar population fitting algorithm as a
prior, we expect that the SFH of galaxies could be better constrained.
