Using the magnetic coupling of two resonant coils, the aim of medium distance and power transmission can be achieved wirelessly. However，existing researches have shown that a frequency splitting phenomenon will occur when the magnetically coupled resonators are in over-coupled region，thus the frequency of exciting source becomes an important constraint factor for power increasing in the transmission. Moreover, because of the random feature of the distance between the transmitter and receiver，it is difficult to ensure the coincidence of the received and rated power. In order to improve the transmission power and the stability of the energy, system modeling and analysis are performed. It is found that Royer oscillator circuit can be applied to track the frequency points of maximum transmission power in real time. In addition, the received and rated power can be matched by the means of power control based on feedback link. It is shown that the system can realize a stable power transmission of 5 W within the distance of 12 cm in the experiments by means of Royer oscillator and boost circuit，which accomplishes the frequency tracking and power adjustment of the Wireless Power Transmission(WPT)，and verifies the effectiveness of the optimal control in the energy transfer process.