The process of absorbing water vapor into triethylene glycol (TEG) solutions is achieved in two steps. In the first step, water vapor is condensed into water droplets on the gas-liquid interface. The second step involves the dissolution of water droplets into the TEG solution as a result of the change in surface tension in the surface thin film. This study is focused on the effects of the surface tension gradient on mass transfer performance of the absorption process. An investigation of the disturbance induced by the surface tension gradient and an evaluation of the mass transfer behavior were conducted. As noted, the phenomenon of fluid flow in the surface thin film due to the surface tension gradient is termed the Marangoni effect, and the induced convection is usually termed Marangoni convection. To discuss the relationship between the Marangoni effect and the mass transfer performance, the surface tension of the liquid desiccant was measured under different temperatures and concentrations during experimental runs. The conventional mass transfer correlation was modified by using the term of the M index, which combines the surface tension gradient and the driving force of mass transfer to explain Marangoni effects. This improves the average error between predicted values and experimental data significantly.