Abstract: Aiming at the poor development effect by cold waterflooding of Jingguan?2block, the properties of crude oil were qualitatively analyzed, the reservoir cold damage was studied by water injection well抯 temperature buildup testing and waterflooding experiment. The thermodynamic method was used to determine the optimal injection temperature based on solving the numerical model of reservoir. Furthermore, the development efforts under cold and hot water displacement were compared and the interwell temperature field distribution was predicted by reservoir numerical simulation. The result shows that temperature is a very sensitive parameter with oiling. Varying degrees of cold damage is a consequence of paraffin deposition and reservoir channel plug from decline of temperature below the cloud point temperature. Simultaneously, precipitated paraffin changes the rheological properties of crude oil thereby increasing the filtration resistance and reducing the oil displacement efficiency. The hot water displacement process can effectively improve the high pour?point oil reservoir development effect, increasing oil mobility and enhancing oil recovery. Nevertheless, water injection temperature is not as high as possible, the limit of development cost must be taken into account with the increase of displacement efficiency, the final optimal water injection temperature of Jingguan?2block is80℃