In this paper, alpha-diimine nickel catalyst without immobilization was successfully used for one-step synthesis of spherical hollow polyethylene particles at mild condition (1.0 MPa, 25 degrees C) by conducting coordination dispersion polymerization. It was found 2-methyl-2-pentanol (MP) played a key role in the formation of the unusual hollow particular morphology. By varying the addition amount of MP, changing the bulky groups of alkyl aluminum, and adjusting the concentration of nickel catalyst, the particle size was finely tuned. A plausible mechanism was proposed to interpret the formation of these polyethylene hollow particles. (C) 2020 Elsevier Inc. All rights reserved.