Abstract: Scaling of water-injected system in the development of the oilfield is a common problem, which badly impacts on the safety of oil production. Based on the study of related articles at home and abroad, the influence of temperature, flowing viscosity of fluid.hardness of water, salt content. pH value, pressure, ion concentration and water salinity on the scaling of water-injected system is analyzed and results obtained will help to instruct safe running of water injection, reduce cost and increase oil productivity.