This　paper　presents　the　propagation　characteristics　of　sinusoidal　wave　that　from　an　intestineingested　in　simple　model　of　the　human　at　the　403MHz　and　923MHz,　by　using　the　finite-difference　time-domain　method　through　discrete　Maxwell＇s　equations.　This　simulation　results　exhibit　the　wave　propagation　process.　These　results　can　help　us　explain　the　phenomenon,　the　attenuation　of　the　electromagnetic　wave　in　human　tissues　is　different　due　to　dielectric　property　in　various　human　tissues　and　different　frequency　that　we　choose.　This　results　are　useful　for　the　design　of　wireless　communications　module　of　an　ingestible　device,　e.g　wireless　capsule　endoscope.　©2021　IEEE.