Nine different decompression tables were evaluated by the method of bubble formation in the agarose gel, the result of which is summarized as follows: 1) The number of bubbles formed in the agarose gel corresponded well with the exposed pressure. 2) The technique of this method was simple and the number of bubbles was accurately counted. 3) This method was considered useful for examining the decompression tables. 4) Using an equation obtained from the experiment with the same agarose gel, the critical number of bubbles at the encl of decompression was found to be 6.6. 5) From this point of view, the R.N.P.L. Table of England and Mano’s Model I Table were considered to be excellent. 6) The first stop at the deeper level during the ascent resulted in a smaller number of bubbles at the end of decompression, indicating the effectiveness of this procedure for the prevention of decompression sickness.