Abstract: In order to achieve the rational distribution of traffic flow in a road network,Variable Message Signs (VMS) can guide drivers to choose optimal route through dynamic traffic information.In this study,a mutti-category ordinal Logit model has been developed based on a stated preference survey,and the factors which have effects on drivers while choosing route under VMS condition has been analyzed.The results show that the main affecting factors are age,travel distance,travel path,degree of trust in VMS and frequency of change route.Among personal properties,age is the most effective factor.As to travelling properties,drivers are sensitive to travel distance and travel path.In compliant properties towards VMS,higher degree of trust in VMS brings more probability when drivers choose to switch path according to guidance information provided by VMS;drivers with high frequency of changing route are more likely to switch path.