High pressure water jet removing impurities in formations is a new way developed recently to increase oil production and injected-water. First of all, this paper presents the main reasons of formation plugging, the basic principles of high pressure rotating water jets removing impurities and the laws of the tool's rotating speeds, impact pressure and relations between impact pressure and nozzle stand-off. The field-test results obtained from over 500 oil and water-injection wells in Liaohe, Shengli, Zhongyuan, Huabei etc., indicate that this technology has such advantages as simplicity of use, cost effective, high success rate, wide adaptability, and significant effectiveness. From this, it is profitable and promising to increase production in highly water-cut oilfields.