Due to limited knowledge of ground conditions and absence of practical analytical methods for tunnel design, tunnels in Taiwan have so far been designed on the basis of past experiences rather than the analytical approach. To develop a strictly formatted design criteria is not appropriate. As more tunnels will be constructed in the future, descriptive tunnel design guide is needed for planning and design of tunnels and for correcting some bad habits of the local tunneling operations. The guide which consist s of three parts, i.e., General, Investigation and Testing, and Design, is mainly based on empirical practices with consideration of recent theoretical developments.