The polymerization of h-valerolactone (delta-VL) using 3-phenyl-1-propanol (3-Ph-PrOH) as the initiator and trifluoromethanesulfonimide (HNTf2) as the catalyst in CH2Cl2 at 27 degrees C with the [delta-VL](0)/[3-Ph-PrOH](0)/[HNTf2](0) ratio of 100:1:0.1 proceeded homogeneously to afford a poly(delta-valerolactone) (PVL) with a narrow polydispersity index. The molecular weight determined from the H-1 NMR analysis, M-n = 9600 g mol(-1) fairly agreed with that estimated from the initial ratio of [delta-VI](0)/[3-Ph-PrOH](0), M-n,M-theo = 9400 g mol(-1). In addition, the kinetic and chain extension experiments confirmed that the HNTf2-catalyzed ROP proceeded in a living fashion. The H-1 NM R, SEC, and MALDI-TOF MS measurements of the obtained PVL clearly indicated the presence of the initiator residue at the chain end, showing that the HNTf2-catalyzed ROP of delta-VL proceeded through a living mechanism. The HNTf2-catalyzed ROP of delta-VL with functional initiators, such as 6-azido-1-hexanol, 2,3,4,5,6-pentafluorobenzyl alcohol, and N-(2-hydroxyethyl)maleimide, successfully afforded the corresponding end-functionalized PVL with a precise molecular control.