Abstract: Aiming at the failures of water injection string in Tuha Oilfield, the author analyzed systemically from shaft status, pipe string and tool design to the management in the later period. The main reasons for string failure included packer failure caused by pressure fluctuation of injection water or by piston dislocation while backwashing, leakage of tubing string, and quality of work, etc. Daily management of water injection should be strengthened to increase the duration of strings. The analysis results and measures proposed are of guidance to increase the duration of strings of water injection wells in Tuha and other oilfields with the similar situations.