It is very important for cavitation research to grasp beforehand the bubble distribution condition in media. The purpose of this study is to realize a real-time indication system of estimated bubble distribution condition in media using measured acoustic attenuation data. For this purpose, theoretical studies on the relation between the bubble distribution condition and the acoustic attenuation and the boundary conditions of the relation were executed and are shown. The estimation method of the bubble distribution condition from acoustic attenuation data is also shown and error/fluctuation occurrence mechanics on the estimation are discussed.