Blood clots in the legs depending on inactivity of the passengers who travel by sea, air or land vehicles and the office workers who stay non movement on the desk for long times will be prevented with my thrombosis-preventive pedal system for vehicle and/or underdesk invention. Blood circulation slowdown as a result of long-sitting period causes thrombosis in the veins or in the artery and that thrombosis carried by the blood to the brain, heart and lungs causes cardiac or cerebral infarction or pulmonary lung embolism. People die or be paralyzed for life as a result of this common issue. The slogan of the World Thrombosis Day ' Move Against Thrombosis ' refers to this solution. My invention supplies movement activity facility for the immobilized still people to move their legs while sitting. My invention which I entitle it as ' Thrombosis preventive pedal system for vehicles and for underdesks is: It is a bicycle pedal system will be designed according to the vehicle's physical conditions. Its operating system may be mechanical or magnetic or manually, whichever preffered. The pedal system which gives the people possibility for moving during their sitting period, may be designed as moveable by pushing with foot on the resistant sprigs. Also this pedal system will be created vertical, horizontal or elliptical bicycle mechanism； depending on the vehicle's physical conditons. Also The motion energy which comes out doe to passenger's pedaling will transport to the dynamo or battery, and charged electric current will be used for the vehicle's needs.Les caillots sanguins dans les jambes résultant de l'inactivité de passagers qui se déplacent dans des véhicules marins, aériens et terrestres et de travailleurs de bureau qui restent sans bouger pendant de longues périodes pourront être empêchés au moyen d'un système de pédale anti-thrombose pour véhicules et/ou dessous de bureau selon l'invention. Le ralentissement de la circulation sanguine provoqué par une longue période
