the first YZ series DC motor and YJ series AC variable frequency asynchronous motor was developed successfully by Yongji company, which put an end to the history of relying on imported motors and which filled the gap in domestic market. The company takes charge of drafting the industry standard of national oil drilling motor. The DC ,AC motors covers more than 160 type and 23 power level, ranging from 200kw to 1600kw. Which are equipped in the 1000mâ€”12000m oil rigs running in 14 Petroleum Administrative Bureaus such as: Daqing, Shengli, Liaohe, Huabei, Xinjiang, Changqing etc. and some overseas oil field such as; Russia,ï¿½ Venezuela, Egypt etc. The domestic market share reaches 77% in 2008. Currently, the oil drilling motor is experiencing a rapid development from land to sea, from China to international market.