A drive support system can provide drive support information on traveling of an own vehicle with respect to another vehicle based on positional information. The drive support system can include a drive support level determination part which changes the degree of offer of the drive support information in a stepwise manner corresponding to a traveling area of the own vehicle. An error occurrence area memory part stores an area where an error in the positional information meets or exceeds a predetermined level in advance along with map information. A degree of offer of the drive support information is limited when the own vehicle is present within an area where an error in the positional information meets or exceeds a predetermined level.