An immobilization strategy of catalytic TiCl4 on polyhedral oligomeric silsesquioxanes (POSSs) is developed, which features both robustness and equivalence of active sites in ethylene polymerization thanks to the non-covalent O-Ti coordination. The symmetric structure of POSS homogenizes the coordination of the TiCl4 molecules, enabling considerable activity in the synthesis of narrowly distributed polyethylene.