New sesquiterpene esters, triptogelin A-5, A-6, A-7, A-8 and A-9 have been isolated from the achenes of Tripterygium wilfordii Hook fil. var. regelii and their structures have been established on the basis of spectroscopic and chemical evidence. The structural elucidation of triptogelin A-6, was confused by ester rearrangement which occurred during partial hydrolysis, but the structure was eventually determined by using 2D NMR spectrum.