There are obvious differences in attracting FDI between the East and the Midwest of China. The investment environment is the main reason. To the Midwest, it is important to analyze the factors to affect FDI in order to improve the investment environment. At present, most of the researches about location determinants of FDI are focused on the location modeling and using Statistical data. The authors designed indexes to describe the location factors and investigated the foreign invest companies in Chongqing by questionnaire. Then analyzed the data collected from questionnaires by Principle Component Analysis and abstract the main components finally. The CITC and at suggest that the location factors are reliable. A system is constructed including six main components and 17 descriptive factors.