Body channel communication (BCC) has the potential to achieve better energy efficiency over other conventional wireless communication schemes, thus becomes a promising solution for the wireless body area network. To deal with the fading and dynamic variation challenges of BCC, the technique of orthogonal frequency-division multiplexing (OFDM) is a promising candidate. However, some basic issues in OFDM including the pilot design and the modulating methods have not been analyzed for BCC. The contribution of this paper includes proposing a dynamic channel model of BCC for system level designing, analyzing the pilot design method, and proposing an adaptive modulating algorithm for BCC. Practical communication experiments based on software define radio are also implemented to validate the the effectiveness of the pilot design method and the modulating algorithm.