Based on the review of the flexible transmission planning, two novel flexible t planning models with scenario technique are proposed. One is to minimize the expectation value of construction costs; the other is to minimize the deviation from the best expansion plans of different scenarios, both models are based on scenarios occurrence probability and the physical constraints are considered with flexible principle. The proposed models don’t pursue the optimal solution for a specific scenario but the comprehensive optimal one that has the best adaptability to all the scenarios according to the occurrence probabilities. The classic Garver 6-bus system illustrates and justifies the feasibility of the models.