To address the issue of strong ability of southern acidic soils to adsorb and fixphosphorus specifically，this study used a micro-area experiment to investigate the effects ofcombined applications ofbiochar(40，60 and 80 t/hm²) and reduced phosphate-fertilizer(P 2O575，60，45 and 30 kg/hm²)on the contents of different forms ofphosphorus. Additional treatment was set up ascontrol(CK).CK was fertilization of P2O5 75 kg/hm²without biocharapplication.The results were asfollows:(1)Combined applications of biochar and reduced phosphate fertilizer significantly increased the content of totalphosphorus，availablephosphorus，resinphosphorus，sodium bicarbonate inorganicphosphorus，diluted hydrochloric acid phosphorus，but significantly decreased the content ofresidual phosphorus.(2)The treatments of ≥45 kg/hm² phosphorus fertilizer application significantly increased soil total phosphorus and available phosphorus by 17.1%-46.7% and32.5%-76.3%，compared with thecontrol.(3)The treatments of ≥45 kg/hm² phosphorus fertilizer application significantly increased the contents of soil resin phosphorus and sodium bicarbonate inorganic phosphorus by 50.8%-160.3% and36.1%-118.3%，respectively，compared with thecontrol.(4)Compared with thecontrol，phosphorus fertilizer reduction resulted in a decrease in soil organic phosphorus content of sodium hydroxide by38.4%-39.8%，but there was no significant difference in soil inorganic phosphorus content of sodium hydroxide betweentreatments.(5)The content of diluted hydrochloric acid phosphorus was significantly increased by 57.9%-352.1% after biocharapplication，compared with thecontrol.The organic content of concentrated hydrochloric phosphorus was significantly lower in the phosphorus fertilizer reduction treatment than in the normal phosphorusapplication with biochar. The inorganic content of concentrated hydrochloric phosphorus was significantly lower in the phosphorus fertilization level of 30 kg/hm² than in the other phosphorus fertilization and biochar treatmentcombinations.The application of biochar significantly reduced the contentof residual phosphorus in thesoil.(6)The contents of soil total phosphorus and available phosphorus were positively correlated with the contents ofresin phosphorus，inorganic phosphorus insodiumbicarbonate，and diluted hydrochloric acidphosphorus.Inconclusion，biochar application is beneficial to improve the phosphorus content of the acidic southern paddysoil，promote the conversion of organic phosphorus to inorganic phosphorus and improve theeffectiveness of soilphosphorus，on which the phosphorus fertilizer application can be as low as 45 kg/hm².