The distributed power control strategy is investigated, which works in the spectrum-sharing femtocell two-tier network. The aggregate interference threshold, which the macrocell can tolerant, is regarded as the allocated resource. The femtocell users compete with each other and purchase it. So the Stackelberg game model of the macrocell and femtocell is built, and the non-cooperative game model of femtocell users is established. Then the existence and uniqueness of Nash equilibrium in the non-cooperative game are analyzed. The distributed power adjustment algorithm is given to guide the femtocell users to compete with each other rationally in non-cooperative pattern. The simulation examples are presented to verify the effectiveness of the proposed algorithm.