Fuzzy control method is utilized in many fields. Fuzzy inflow control model on urban expressway is one of the applications of fuzzy control. The actual traffic control is performed by human operators who are always making decisions with many environmental condition around the urban expressway. The objective of the study is to investigate the establishment of fuzzy inflow control model and to study its ability to make alternative judgement. Firstly, the fundamental method of fuzzy reasoning is introduced. Secondly, the simple model for on-ramp control on Hanshin expressway is built and investigated outputs' variation by the change of the model's structure. Lastly, some problems of the model establishment and ways of their solutions are also reported.