Nitrogen solubility in liquid Fe and Fe-C alloys has been measured by the levitation melting method under 1 atm N₂pressure. Experiments were carried out at the temperature range of 1774 - 2097˚K and carbon content of 0 - 5.06wt%. The nitrogen solubilities measured in pure Fe and Fe-C alloys were log (wt%N)_(Fe) = －424/T - 1.129 and log (wt%N)_(Fe-C)＝ -[424/T＋1.129＋(%C)/19.14{5447/T-0.612}＋(%C)＾2/19.14 2478/T- 1.265]