With the promotion of“existed/incremental production”management mode in oilfield，previous optimization model cannot meet the overall requirements of oilfield development planning. According to the reality of the middle-long term development planning of the oilfield，a concept for exited/incremental production suitable for the development planning was defined. An optimization model of incremental production composition was established taking new wells in developed area and undeveloped area as decision variables，actual oilfield requirements，relations and laws as constraint factors，and the maximum profit and minimum investment and cost as the goal. And then integrated optimization of reserves，workload，oil production，investment，cost and profit may be realized. The model was solved by using interior-point method，and was applied to development planning of certain waterflooding oilfield for the“13th Five-year Plan”. The application indicates that the benefits of new wells in the undeveloped areas are much more than those in the developed areas. So all remaining investments turn to new wells in the undeveloped areas，which reflects the optimization for benefit-centered planning after the minimum demands for the developed areas were met. The established model provides the ideas and methods for the optimized decision-making under“existed/incremental production”management mode.