  In this paper, we give a map from matrices to a commutative geometry from a
bound state of a D2-brane and N D0-branes. For this, tachyons in auxiliary
unstable D-brane system describing the bound state play crucial roles. We found
the map obtained in this way coincides with the recent proposals. We also
consider the map from the geometry to matrices in a large N limit and argue
that the map is a matrix regularization of geometry.
