The transmission factor of a dipole to dipole and a loop to loop through homogenous human muscle equivalent material is investigated using the FDTD analysis. The transmission factors of the dipole system and the loop system are compared and the optimization of antenna type and the optimal frequency is also discussed. In the case of dipole system, a local maximum of transmission factor is observed at frequency domain. In the case of loop system, the transmission factor decreases as frequency increases monotonously. The transmission factor of loop system is larger than that of the dipole system in the low frequency region, while the performances of both two systems are almost the same in the high frequency region.