The present invention relates to a preparation method of a polypropylene and a polypropylene obtained therefrom. More specifically, it relates to a method of preparing a polypropylene by using a catalyst that includes a novel metallocene compound having an excellent polymerization activity, and a polypropylene obtained by the method.According to the present invention, since the polypropylene is prepared by polymerizing propylene by using a novel metallocene compound having an excellent polymerization activity and hydrogen reactivity, the properties of the polypropylene can be easily controlled and the polypropylene having excellent mechanical properties can be obtained.