A new lower rim substituted calix[8]arene bearing eight phosphine oxide moieties has been synthesized. The structure of 5,11,17,23,29,35,41,47-octa(1,1,3,3-tetramethylbutyl)-49,50,51,52,53,54,55,56-octakis(dimethylphosphinoylmethyleneoxy)calix[8]arene (S) was identified and confirmed by elemental analysis, IR-, H-1, C-13 and P-31-{H-1} NMR spectroscopy as well as by ES-mass spectrometry.