Abstract: Efficient utilizations of pulping wastes were far more enough due to their complex chemical compositions. A novel water-reducer (PLGN) was grafted by copolymerizing lignosulfonates from pulping wastes with naphthalenesulfonate intermediates. Researches were carried out on the effects of PLGN on cement pastes. It can be found that, the fluidity of cement paste with PLGN was significantly improved and setting retardation was clearly observed. The hydration rate was slightly accelerated during the hydration starting period and the hydration induction period was widely extended with no impact on the second hydration peak value. Results also show that, the hydration degrees of cement pastes with PLGN in later ages were increased. The microstructures of hardened cement paste were modified by PLGN with better uniformity and compactness.