In this thesis we intend to study about geometrodynamics of 4 d spacetime. This study investigates in a midisuperspace model. We assume that spacetime has spherically symmetry, in the other words that is taken to be diffeomorphic to R × ? , where R is direction of time and the space-like hypersurface ? is and ? stretches all of Kruskal diagram. The spherically symmetric metric on the hypersurface is given by . Metric depends only on two functions ?( r, t ), R ( r, t ) and r is radial coordinate. First the cutvature coordinates R, T are given on the ?, then they are turned into canonical coordinates R ( r ), T ( r ) in a phase space. So we countinue by setting a set canonial coordinate by diong canonical transformations that will be turned to Kruskal coordinate easily. This approach is efficient to study about primordial black holes in cosmology theory framework. In the following we will study asymptotically behavior and falloff of the canonical variables in infinity by using Schwarzchild metric. By adding boundary term and getting canonical action, we can quantize these Schwarzchild-like black holes. Finally we recover only one degree of freedom has remand for primordial black holes that is mass of black holes and its canonical conjugate momentum is difference of parametrization times at r ? ? and r ? ?? .