The solubilities of N2O in aqueous diethylenetriamine (DETA) solution at different mass fractions (15, 30, 45, 60, 75, 90, and 100) % of DETA were measured at different temperatures of (297.7 to 360.7) K. The solubility of N2O in aqueous DETA solution is strongly dependent on both temperature and mass fraction of DETA. A semiempirical model considering the excess quantity of Henry's constant was correlated with the Redlich-Kister equation. The model gave satisfactory agreement with the experimental data.