The transformation of added phosphorus into distinct fractions during incubation of three calcareous soils of different parent materials was studied. The soils were selected from agricultural fields of northern Karnataka. An incubation study was conducted to know the extent of release or transformation of different forms of phosphorus in the soil after the addition of fertilizers, DAP and KH2PO4. Applied phosphorous transformed mostly into Pedogenic Ca-P followed by reductant-soluble P in all the three soils. Al- and Fe- bound P fraction was higher in red soil than in brown or black soil, despite having least amount of free Fe-oxide content. The mild reductant-soluble P decreased rapidly and vanished after first few days of incubation. None of the fertilizers used did contribute to this fraction of P. The reductant-soluble P increased to about 5 times (up to 500 mg kg-1) by the end of first week of incubation and remained so during remaining period of incubation. The lithogenic apatite did not show much variation either from the start or during incubation.