In absorption refrigeration technology, it is well known that the water vapor absorption into the lithium bromide (LiBr) aqueous solution is enhanced by the addition of surfactant. The Marangoni effect plays a role but its mechanism is not clearly understood yet. In the present study, the existence of instability due to Marangoni effect was investigated using the linear stability analysis, based on the salting out effect. Then the vapor absorption augmentation was estimated by the numerical simulation of cellular convection. Both theoretical results qualitatively agree well with the experimental ones.