A simple method was developed for measuring phosphorus (P) mineralisation in soil using an anion exchange membrane. Labile inorganic phosphate was first removed from the soil by means of the membrane. The soil samples were then filtered on GF/C papers and incubated moist under aerobic conditions for seven days at 39°C. The inorganic phosphate produced during incubation was extracted using a second extraction with the anion exchange membrane to give a measure of phosphorus mineralisation. The method was applied to 17 soil samples taken from Inceptisols, Andisols, and Spodosols under pasture and pine forest.