The polymerization of vinyl chloride (VC) with n- or tert-butyllithium (n- or tert-BuLi) in the presence of allyl bromide (ABr) was evaluated for synthesizing the vinyl-terminated poly(vinyl chloride) macromonomer (PVCM). The structure of the product was based on the H-1 NMR and H-H COSY spectra. The functionality of the vinyl group was over 90%. To determine the detailed structure of PVCM, a MALDI-TOF-MS analysis of the PVCM derivative (PVC-DEA center dot HCl) obtained by the thiol-ene reaction of the macromonomer with 2-(diethylamino)ethanethiol hydrochloride was conducted. The MALDI mass spectrum of PVC-DEA center dot HCI in the absence of any ionizers exhibited only one series of ions repeating at an interval of 62 Da (which was the repeating VC unit), and the mass distribution agreed well with the calculated value of PVC-DEA center dot H+ without any defect structures. The syndiotactic rich PVC was found to be synthesized by the polymerization of VC with BuLi in the presence of ABr. Especially, the obtained PVCM using tert-BuLi (ABr/BuLi = 10) was the most syndiotactic polymer (rr > 80%).