The effect of applying phosphorus (P) on high P test soils (STP) is a concern due to possible changes in the water, soil, and crop quality. Increasing P in STP may change relationships within P fraction and change the P availability in soil sorption sides. The purpose of this study was to determine the effects of the application of triple superphosphate (TSP) swine Manure (SM) and biosolids (BS) on soil fraction P forms in a STP soil. An incubation study was conducted in a chamber with controlled temperature and light. The treatments consisted of mixing 5 g of soil from 4 different depths with TSP, SM, and BS at a low and a high rate. A sequential fractionation for inorganic and organic P forms was performed. Soil P was higher in BS than in SM and TSP treatments in all P fractions. Increasing P rate increased soil extractable P in soils. The application of BS, SM, and TSP to high STP soil resulted in differences in extractable P fractions in our soil. The proportion of soil P fractions were: NaOH-Po > HCl-P > NaHCO3-Pi > H2SO4-P. The NaHCO3-Pi, NaOH-Pi and HCl-P fractions increased in BS treatments more than in others. This suggests that BS has a potential to increase others P fractions due to the addition of Al and Fe associated with P sorption sites and an increase in labile P. Swine manure and BS increased the HCl-P suggesting that this source either enhanced Ca-P bonding or contained Ca-phosphate. Most soil P fractions were affected by the P source x rate interaction. This indicates that an increase of P content on a STP soil affected P extraction differently depending upon the source.