Abstract: This paper aimed at systematically exploring the right development way of intercity railway (IR) by estimating the strategic impacts of IR construction on regional economy, society and environment in Gansu province, which showed the characteristics of Northwest China. By choosing Lanzhou-Zhongchuan IR as an instance and introducing scenario analysis method, the opponent viewpoints, the critical conflicts and the right construction scheme in the project planning was systematically analyzed. The paper showed the key technical difficulties and breakthroughs of our research, such as weight determination of necessity factor, forecasting traffic demand of the IR, regional economic impact and so on. Finally, a framework of strategic impact analysis was designed in the paper, so as to make decision more rationally in the IR planning. It is easy to find that the research result and the conclusion accord with the actual situation of Lanzhou-Zhongchuan IR by investigation.