We proposed a convenient method for the synthesis of C-unalkylated calix[4]resorcinarene octamethyl ether by the HCl-catalyzed condensation of 1,3-dimethoxybenzene with paraformaldehyde in 2-ethoxyethanol. The conformation of the C-unalkylated calix[4]resorcinarene was preferentially chair-like and it changed to a boat-like by heating it in bulk and solution.