A navigation system utilizing a warning generating apparatus is disclosed. The warning generating apparatus includes a data receiving unit for receiving route guidance information data and current weather/time information from an external information center; a data analyzing unit for judging whether warning data has been included in the route guidance information data outputted from the data receiving unit; a sensor for sensing a current travel speed of a movable body; a restricted warning generating unit for receiving the route guidance information data having the warning data from the data analyzing unit if the route guidance information data is judged to include the warning data, and for determining whether it will output a warning for the warning data, based on warning generation conditions stored in advance according to a kind of the warning data; and a warning/guidance output unit for outputting warning information when the warning information has been transmitted after the warning has been determined to be outputted by the restricted warning generating unit.