The rate of interphase mass transfer between the bubble and emulsion phases of a bubbling fluidized bed is of primary importance in all models for fluidized bed reactors. Many, experimental studies have, beers reported, however, all these investigations have been carried out in fluidized beds operated at room temperature.. In this work, the effect of the bed temperature on the interphase mass transfers reported. Single bubbles containing argon - used as a tracer - were injected into an incipiently fluidized bed maintained at the required,temperature; The change-in argon concentration in the bubble was measured using a suction probe connected to a mass spectrometer. The effects of bed particle type and size, bubble size, and bed temperature on the mass transfer coefficient were examined experimentally. The interphase mass transfer coefficient was found to decrease with the increase in bed temperature and bubble size, and increase slightly with increase in particle size. Experimental data obtained in this study were compared with some frequently used correlations for estimation of the mass transfer coefficient.