Absorption of gaseous species into stationary droplets is a fundamental interest of mass transfer between liquid droplets and ambient gas, which plays a key role in atmospheric environment control and many indus trial applications. In this paper, two different considerations including equilibrium and non-eq uilibrium relations at the interface are used to analyze and predict the absorption time for a physical absorption at a relatively low so lubility of gas. For the equilibrium pattern, in the beginning period of absorption, the mass transfer rate is considerably rapid and afterward becomes slower and slower and finally comes to almost zero as the droplet concentration closes to the saturated value. Diferently, when the non-eq uilibrium model is adopted, the interfac ial concentration increases grad ually with the bulk concentration of liquid droplet, and the absorption rate mildly decelerates with the increase of bulk one throughout the process, which lead s to a longer absorption time. Bas ed on the difus ion eq uation of species, the concentration distribution within the droplet at ditierent times is computed. A solution for CO2 abso rption into a small water droplet is given.