A series of polycarboxylate superplasticizers were synthesized with methacrylic acid ( MAA) ,sodium methylacrylamide ( MAS) and methoxy polyethylene glycol methacrylate( PMA45) as monomers,and ammonium persulfate ( APS) as an initiator. Then,the effects of raw material proportion on the early-strength performance of polycarboxylate superplasticizers were investigated by measuring the early strength of harden mortar and by using a scanning electron microscope to observe the morphology of early cement stone. The results show that the earlystrength performance of the superplasticizers first increases and then decreases with the increase of the dosage of PMA45,and increases with the increase of the dosages of MAA and MAS as well as with the decrease of the relative molecular mass of the superplasticizers,which means that the superplasticizers with optimal density of side chain ( polyethyleneglycol) ,high contents of carboxylate and sulfonate,and low relative molecular mass are of excellent early-strength performance.