Abstract: Xanthan gum profile control agent has performances of viscosifying,salt-resisting and shear-resisting,is suitable for large dosage profile control of deep well in high salinity formation.This paper introduces the preparation,indoor core simulation testing,technical property,field testing results of xanthan gum.It shows that xanthan gum can improve injection-production behavior of well group,increase utilization factor of water injection well and enhance oil recovery of waterflooding reservoir.