To improve use efficiency of phosphorus in farming, a phosphate-solubilizing strain of fungi (PSF) labeled as B1-A was isolated from the rhizosphere of peanuts growing in red soil and identified as Aspergillus niger according to its colonial morphological characteristics and ITS rDNA sequence analysis. In the culture prepared out of two hard-to-dissolve phosphates (FePO₄ and AlPO₄), B1-A was added at a rate of 1%, 3% and 5% separately. It was found that the P dissolution rate in and pH of the culture varied with the time, that a significant negative correlation existed between the rate and the pH, and that the former was also related to B1-A inoculation rate, incubation time and the concentration of rock phosphate powder (RPP) in the solution as well. Results show that B1-A demonstrated its highest capability when the solution was 3 g L^-1 in Yunnan and 5 g L^-1 in Jiangxi RPP concentration, inoculated with 3%~5% of B1-A, and incubated for 168 hours. B1-A was quite good at dissolving tricalium phosphate, aluminium phosphate, ferric phosphate and RPP, and might dissolve as much as 418.7, 942.3, 242.2 and 177.4 mg L^-1, respectively. So B1-A is a promise microbial resource for development of high efficiency biological phosphorus fertilizer for use in latosolic red soil.