||Windshear is the sudden change of wind speed and/or direction. Many of the aviation accidents in the past few decades were related to occurrence of windshear near the airport. In particular, windshear events associated with the passage of a strong gust front or the occurrence of severe microbursts (strong sudden downdrafts) near the runway are particularly hazardous to aircrafts landing or talking off. In the present study, based on idealized and actual wind observations near an international airport, a mathematical model will be used to analysis and distinguish different types of windshear along the runway. Different headwind, tailwind and cross wind situations can be visualized using this model. An alert system can be made from this result. Idealized and real cases will be used to demonstrate the usefulness of this model.