Macroseismic formula for determining hypocentral depth and its precise calculative method

In this paper, under condition I 1= I 0 and r 1= r 0, proved h=r 0 . That is when meizoseismal region has become epicentral area, the hypocentral depth is equal to the radius of isoseismal curves of epicentral area. It is theoretical standard of hypocentral depth from which the precise calculative methods of macroseismic formula for determining hypocentral depth can be deduced. Comparing the computations with one another indicated that the routine calculative method of complete macroseismic formula for determining hypocentral depth is the optimum selection.