Abstract: This study was conducted to investigate the permeability reduction caused by deposition of strontium sulphate in sandstone cores from mixing of injected sea water and formation water that contained high concentration of strontium ion at various temperatures (50 -80 °C) and differential pressures (100-200 psig). The solubility of strontium sulphate scale formed and how its solubility was affected by changes in salinity and temperatures (40-90 °C) were also studied. The morphology and particle size of scaling crystals formed as shown by Scanning Electron Microscopy (SEM) were also presented. The results showed that a large extent of permeability damage caused by strontium sulphate that deposited on the rock pore surface. The rock permeability decline indicates the influence of the concentration of strontium ions. At higher temperatures, the deposition of SrSO4 scale increases since the solubility of SrSO4 scale decreases with increasing temperature. The deposition of SrSO4 scale during flow of injection waters into porous media was shown by Scanning Electron Microscopy (SEM) micrographs. The results were utilized to build a general reaction rate equation to predict SrSO4 deposition in sandstone cores for a given temperature, brine super-saturation and differential pressures.