A two-step conventional laboratory process was developed for the synthesis of mono-and difunctional linear and three-arm star tert-chlorine-telechelic polyisobutylenes (PIE) with desired molecular weights (MW) and narrow molecular weight distribution (MWD) by living carbocationic polymerization (LCCP). This polymerization method applies easy to handle operations and chemicals. LCCP of isobutylene (IB) was carried out in CH2Cl2 as solvent and with BCl3 as coinitiator in the first step to obtain soluble low MW PIE prepolymer with narrow MWD. This was followed by addition of hexane, TiCl4 and additional monomer in the second step to prepare PIBs with desired MW and narrow MWD in practically any suitable MW region. Comparison of the one-step and two-step processes is also described.