A continuous flow apparatus is set up to study the enzymatic interesterification of palm oil by stearic acid in supercritical carbon dioxide. Domestic edible palm oil is mixed with stearic acid and loaded to a saturation tank in which the oil is extracted by supercritical carbon dioxide. The current of the extraction solution bubbled from the saturation tank is delivered to an enzyme-packed column. In this study, five triglycerides (POP, POS, POO, OOO, and SOO) and two free fatty acids (stearic acid and palmic acid) are selected as indicators to monitor the interesterification. The results show that the Mucor miehei dominantly catalyzes the interesterifications of POP + S much less than POS and POO-S much less than SOO when the stearic acid content in the extraction solution is abundant. A very limited amount of SOS is also irregularly found in the product samples. POS and SOO are rarely produced when the loaded stearic acid is completely elutriated, and the weight fraction of POO is significantly increased by the depletion of POP. It is presumed that the palmitoyl group in the 1,3 position is substituted much more readily, and that the stearic acid is a reactive acyl donor for the interesterification in supercritical carbon dioxide when catalyzed by Mucor miehei. That large amounts of palmic acid are found in the transesterified oil confirms this presumption.