The methods of interpretation of gravity data have been reviewed. Two methods generally used are (1) gravitational attraction directly computed for bodies of various shapes is compared with the observed gravity; and (2) the actual mass density distribution is approximated by an equivalent surface density distribution. No interpretation is unique, for, an infinite number of mass distribution can produce the same gravitational field at all external points. "Second derivative method of interpretation of isolation of gravity anomalies have also been reviewed. The merits and demerits of different formulas have been discussed.