n order to prevent the formation of barium sulfate scale in the process of oilfield development and improve the temperature resistance and salt resistance of anti-scaling agent，by considering anti scaling functional group and relative molecular weight of organic matter，a new BaSO4 scale inhibitor was prepared through aqueous solution polymerization by using acrylic acid（AA），maleic anhydride（MA），2-acrylamino-2-methylpropanesulfonic acid（AMPS）and methyl methacrylate（MMA）as reaction monomer，and（NH4）2S2O8 as initiator. The proportion of raw materials was optimized，and the effects of temperature，dosage and pH value of scale inhibitor on scale prevention rate and the compatibility of scale inhibitor with formation water were studied. The results showed that when the optimal dosage of reaction monomer AA，MA，MAA，AMPS was 30%，52.5%，5%，12.5% and the dosage of（NH4）2S2O8 was 1.5% in terms of total amount of monomer，the molecular weight of the scale inhibitor was close to 9640.69，and the purity of the product was 62.3%. At the gathering and transportation pipeline temperature of 50℃，when the dosage of scale inhibitor was higher than 12.5 mg/L，it had excellent anti-scaling effect of barium sulfate. When the dosage was 100 mg/L，the scale prevention rate could reach more than 85%. The scale inhibitor had a good anti-scale effect in weak alkaline environment.The scale inhibitor had good temperature resistance and could effectively prevent the growth and adhesion of barium sulfate crystal at low concentration. The compatibility of scale inhibitor and formation water was good. The mixture of scale inhibitor and simulated formation water containing various cations could be kept at 50℃ for 24 hrs without precipitation，meeting the requirements of oilfield.