Using α-methallyl-ω-hydroxy poly（ethylene glycol）（HPEG） as macromonomer， a series of polycarboxylate-based superplasticizer（PCE） with different acid-to-ether ratios， side chain length and relative molecular mass were prepared and used as cement grinding aids. The influence of PCE molecular structure on its grinding efficiency was investigated. The results indicate that the optimal grinding efficiency is provided by a PCE with a proper acid-to-ether ratio. Short side chain length and low relative molecular mass are preferred. Compared to the reference， the cement produced with PCE exhibits a decreased water demand for standard consistency， and the compressive strength decreases at 16 h without any loss at 28 d.