In order to improve rheological properties of xanthan gum solutions，long-chain hydrophobic amphoteric xanthan gum（OD-XG）was synthesized by xanthan gum（XG）and hydrophobic cationic etherification reagent that was synthesized using the main raw materials of oleamidopropyl dimethylamine and epichlorohydrin. The rheological properties of OD-XG and XG solutions were studied and compared，including the steady viscosity，flow curve，thixotropy，and viscoelasticity，as well as the temperature resistance and the gel-breaking performance. The results showed that the viscosity of OD-XG solution was significantly higher than that of XG，and the viscosity of 0.6% OD-XG solution（237.97 mPa·s）was increased by 221% compared to the viscosity of 0.6% XG solution（74.12 mPa·s）. The flow curve of OD-XG and XG solution could be fitted by nonlinear co-rotation Jefferys model.The viscoelasticity and thixotropy of OD-XG solution were significantly higher than those of XG solution，and the temperature resistance of OD-XG solution was improved. The reserved viscosity of 0.4% OD-XG solution（70.102 mPa·s）was twice as much as that of 0.4% XG solution（35.135 mPa·s）. The rheological study of gel breaking process showed that，after adding the breaker the gel breaking was completed well.