This study reports a novel one-step method to synthesize a new spherical support for Ziegler-Natta catalyst under moderate condition. The support is obtained from a dispersion system where the particle stabilizer polyvinylpyrrolidone plays a main role to stabilize the spherical particles. The new chemical of the support is CH3CH2OMgOCH(CH2Cl)2, which is first reported here, has been approved by newly filed patents and also confirmed by solution NMR, solid state NMR, pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS), and ICP-MS. The support and catalyst particles have uniform distributions. The catalyst prepared from this support has been evaluated with high activity. The polypropylene obtained has high isotacticity. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41014.