Based on thermodynamic and dynamic calculation of hot metal dephosphorization in a converter, and the analysis of production data of a 300 t dephosphorization converter of Shougang Jingtang Steel Corporation, this paper studies the selective oxidation characteristics of Fe, Si, Mn, C, and P in a hot metal, and the main factors affecting dephosphorization. The phosphorus distribution between hot metal and slag are also discussed. The results show that Si and Mn are oxidized first during oxygen blowing when the oxygen potential increased, and oxidation of P and C occurs. To decrease the hot metal pretreatment temperature to about 1 300~1 350 ℃ and control the slag basicity to about 1.7~2.5 are the key to solving the problem of removing P at high carbon content. Improving the slagging process in a dephosphorization converter combined with high bottom gas stirring intensity can improve the dephosphorization rate.