Abstract: With the rapid growth of natural gas demand and the continuous construction of supporting facilities, the scale of production-transportation-marketing system gets larger and larger, and the Excel-based manual balance mode can no longer satisfy the demand of natural gas production-transportation-marketing planning in terms of work efficiency and balance result. As an important part in the planning of natural gas business, a balance analysis is conducted on the production-transportation-marketing system, and the work tasks can be scheduled much more reasonably based on the analysis result. In this paper, a mathematical model of production-transportation-marketing system was developed with the overall benefit maximization of natural gas industry chain as the target by means of mathematical abstraction and element simplification. The software CPLEX was used as the optimization tool to solve the model. This model has been applied in the efforts for the 13th Five-Year Plan of CNPC’s natural gas industry and the analysis of natural gas production-transportation-marketing. With this model, the target of benefit maximization is reached and the optimization efficiency is increased significantly by allocating the resource market rationally and optimizing the natural gas distribution. It provides the basis for scientific decision-making of natural gas planning.