Abstract: Biphasic solvent is attracted considerable attention due to its huge reduction on regeneration energy. A novel alkanolamine based biphasic solvent DAH containing 50% N, N-diethylethanolamine (DEEA), 25% 2-(2- aminoethylamino) ethanol (AEEA) and 25% H₂O was investigated for degradation performance. It was found that DEEA of main composition in upper phase shown satisfied anti-degradation performance. Only 15.96 % of degradation rate was achieved in 10% CO₂ condition through four weeks degradation process, which was 17.8% lower than benchmark 30wt. % MEA, while AEEA of main composition in lower phase degrades seriously. Approximately half of the free amine was transferred to the degradation product, which was hard to be regenerated. The increase of degradation rate of AEEA was 47.3% compared with aqueous MEA. Oxygen concentration was illustrated as the key affecting factor of degradation process in this case which was proportional to the degradation rate. Eight main degradation products including piperazine, imidazolidone and pyridine derivatives was analyzed by GC-MS technology. Relating degradation mechanism was speculated.