The FDTD method is a numerical technique that can be used to solve electromagnetic boundary value problems in the time domain. This method is excellent in computational efficiency, practicality, and simplicity. In recent years, we have frequently used this method in order to analyze antennas, electromagnetic scattering problems, and so on. However, the electromagnetic boundary value problems which we can analyze by this method are limited because computer memory is limited. In order to overcome this important problem, Rodohan and colleagues recently developed the distributed FDTD method. In this method, the necessary computer memory is provided by several computers and we can analyze problems which need a large computer memory space. In this paper, we first propose a new distributed FDTD method in which the number of communications and the communication costs except for absorbing boundary conditions are half those of the Rodohan method and the absorbing boundary conditions are highly accurate. Second, when we calculated the scattering of a plane wave by a square conducting cylinder with our method and the conventional FDTD method, the results were in agreement. We confirmed the high speed of calculations with our method. Finally, we were able to show the validity and the effect of our method. © 1997 Scripta Technica, Inc. Electron Comm Jpn Pt 2, 80(5): 8–16, 1997 [ABSTRACT FROM AUTHOR]