Abstract: The factors influencing nitrogen content in BOF were analyzed in less slag steelmaking. The results showed that the good equipments of top The factors influencing nitrogen content in BOF were analyzed in less slag steelmaking. The results showed that the good equipments of top oxygen blowing were very important. The nitrogen mass fraction of blowing end in steel could be within 12×10-6 using FeSi for raising temperature. The argon stirring at the BOF bottom in the whole blowing process could decrease nitrogen mass fraction of 3.3×10-6. The nitrogen content would decrease when some coolant were added to the BOF with the carbon mass fraction of 0.3%－0.4%. Reblowing and long tapping time would increase nitrogen content in steel. Through optimized measures the nitrogen mass fraction could be within 15×10-6 at the ladle and meet the demand of low nitrogen steel.