The mass transfer characteristics of a gas dissolution process around a single stationary bubble were investigated experimentally. The two-color laser induced fluorescence (LIF) technique and particle image velocimetry (PIV) were utilized to evaluate the instantaneous planar pH and velocity distributions, respectively. The results show that the development of the pH and the velocity distribution during the dissolution process were properly evaluated. Moreover, the change in mass transfer characteristics were closely correlated with the development in the pH and velocity field.