Abstract: China^’s proven and undeveloped oil reserves increase with time but the undeveloped rate does not change significantly. As of the end of 2013, the undeveloped reserves in the country^’s oil in place are 85.11×10⁸t and the undeveloped rate is 21.9 percent. The undeveloped reserves in the country^’s recoverable reserves are 10.71×10⁸t and the undeveloped rate is 12.5 percent. Based on the analysis of the undeveloped reserves distributed in different basins, owned by different companies and belonging to different types of oil and gas fields, this paper proposes to use new mindset and new technology to solve the issues related to undeveloped oil reserves: (1) Undeveloped oil reserve is a realistic area to increase oil production; (2) Re-evaluate the dynamic and current conditions of proven reserves; (3) Application of suitable technology holds the key to development. So far as the suitable technology is concerned, it is necessary to stress the uniqueness of each block of undeveloped reserve, launch a new round of accurate seismic survey, appropriately introduce tight oil and gas drilling technology and reservoir transformation technology, and push ahead with heavy oil development. The advanced methods should be used for development of oil fields of medium and small sizes while importance is attached to development of condensate oil and gas fields. Finally, the paper proposes that if China^’s three major oil companies want to concentrate their efforts to increase oil production in their business development, they should appropriately reduce the areas of their exploration blocks and concentrate their efforts to improve recovery factor of the developed oil fields and energetically put undeveloped reserves into production for higher investment returns and economic performance.