This paper presents the monitoring process of gas bubbles flow in water using an optical tomography system. The system is aided by an Independent Component Analysis (ICA) algorithm for distinguishing the gas bubbles in pure water. The optical attenuation model is implemented for studying the light transmissions to different media which is water and air. Several quantities of air are inserted using an air pump which is installed at the bottom of a flow pipe in order to produce the gas bubbles flow upwards. The quantity of air is controlled by using a valve and five types of bubble flow are investigated; a single bubble flow, double bubble’s flow, 25% of air opening, 50% of air opening and 100% of air opening. The concentration profiles of the gas bubble flow are constructed. The concentration profile obtained from the experiments shows that the ICA algorithm can be used as a tool for imaging the two-phase flow phase distribution.