This paper describes a high efficiency unidirectional Frequency Shift Keying (FSK) data transmission system using magnetic resonance wireless power transfer (MR-WPT) with the Automatic Tuning Assist Circuit (ATAC) for moving objects. In the proposed system, power and data are transmitted to the same direction at the same time. In the original MR-WPT system with ATAC, when the driving frequency is changed according to data, a certain amount of time is required to shift the other resonant state. This tracking time causes problems such as the decreasing of power transfer efficiency and limitation of data transmission rate. So, in order to overcome these problems, this paper proposes FSK communication system with two ATACs. Since the two ATACs system can reduce the transition time, the MR-WPT with two ATACs can maintain high efficiency power transfer with data. The experimental results show that data transmission by FSK modulation without error can be realized up to 12.5kbps.