Meteorological elements such as radiation, air temperature, humidity and wind velocity can affect root ion absorption through change in transpiration. A kinetic model of root ion absorption integrated with transpiration was proposed in relation to the ion mass flow to root cell membranes driven by transpiration. The ion absorption model integrated with transpiration represented well rates of root ion absorption measured under the different conditions of ion concentration, light intensity and transpiration. The rate of root ion absorption increased with the rate of ion mass flow to root cell membranes, but this increase was leveled off under the conditions with the higher rates of the ion mass flow. This dependency of root ion absorption on the ion mass flow was characterized by differences in the two parameters involved in the transpiration integrated model proposed.