Abstract: The total transport coefficients of nitrogen from reducing slag containing carbon into liquid steel in Al₂O₃ crucible at 1600℃ have been measured. The result shows that β has been related to the panial pressure of nitrogen in gas phase P_N2, β increases with the increase of P_N2 The calculated results of mass balance was shown that under this experimental condition β₀ =3.7×10^-4 cm/s.