In the recent years, a remarkable evolution of the non-radiant wireless power transfer (WPT) system using strong magnetic resonant coupling has been observed, and it has shown more prospects for powering portable devices due to its operating range and efficiency. However, the performance of the system is adversely affected by the coil movement, which is a critical issue for high transfer efficiency. In this paper, a coupling tuning based impedance matching method is proposed to enhance and maximize the transfer efficiency of the system. The matching conditions are derived from power transfer model analysis using equivalent coil circuit model for optimum transfer efficiency. A simulation setup is developed in an electric automatic tool to testify the viability of the proposed technique, and verified against theoretical data. Applying this technique, the extracted  shows more than 9 dB improvement at both the strong and weak coupling regimes, and results transfer efficiency over 90% at close coil distance without changing the operating frequency. Compared to the conventional fixed coupling and LC circuit based matching technique, the proposed method shows efficiency enhancement about 9% - 20% at different coupling conditions.