This paper presents research activity of the body area channel related studies by Tokyo Institute of Technology and National Information and Communications Technology, Japan. One of our goal is to make a practical wearable body area network propagation channel model during arbitrary body motions. First, we present the numerical simulated electromagnetic wave propagation wearable body area network channel during various human motions at 403.5 MHz. Second we present modeling dynamic on-body channel based on the three dimensional motion of on-body antennas. The simulation results were verified to the measured channel responses from the network analyzer operated simultaneously with motion capture.