Abstract: The study on radiolysis products of gamma-irradiated N,N,N’,N’-tetrabutyl-3-oxa-pentanediamide (TBOPDA) is very useful towards the extractant stability. IR and headspace solid-phase microextraction combined with gas chromatography/mass spectrometry(SPME-GC/MS) are used in the research. By comparisons with standard substances, dibutylamine and N,N-dibutylformamide are comfirmed to be the major radiolysis products. The influences of irradiation on TBOPDA and dibutylamine are quantitated by using headspace SPME-GC and HPLC. According to the experiment results, the possible ways of degradation are also proposed.