[en] Determination of actinide elements in spent nuclear fuels is important for a source term evaluation, burnup credit evaluation and actinide inventory. In this study, transuranic elements such as Pu, Np, Am and Cm were determined by an alpha spectrometry in high burnup spent nuclear fuel samples ranging from 36 to 55 GWD/MtU as a burnup. The used separation method was an anion exchange chromatography and/or a di ethylhexyl phosphoric acid(HDEHP) extraction chromatography. The separated elements were electrodeposited. Alpha spectrometry was applied for ²³⁸Pu, ²³⁹Pu , ²⁴⁰Pu, ²³⁷Np, ²⁴¹Am, ²⁴⁴Cm and ²⁴²Cm using ²⁴²Pu and ²⁴³Am as the tracers, respectively. Especially, for ²³⁷Np, a spike addition technique was adopted using ²³⁹Np as a spike because these spent nuclear fuel samples contain a considerable amount of ²³⁹Np. The determined contents of transuranic elements were compared with those calculated by the Origen-2 code