The circumnuclear environment in M31

Studies of galactic circumnuclear environments is important to our understanding of the feeding and feedback of the central super-massive black hole and in turn the global evolution of the host galaxy. We present an observational overview of the circumnuclear environment in M31 and a tentative understanding of its regulation. Notes on selected open issues, as well as on a comparison with the Galactic Center and other extragalactic circumnuclear environments, are also presented.