The Graph Theory is the study of graphs, mathematical structures used to model pairwise relations between objects from a certain collection. It has has a surprising number of applications: in physics, biology, chemistry, social, commerce, and computer science. In this book we view one part of Graph theory called route problems. The route problem contains a lot of diffente problems. For example the Travelling Salesman Problem is the problem of finding a tour that visits each cityexactly once and that minimises the total distance travelled. Many tour has been founded thank to TPS for example The Sweden tour is 24.978 -cities problem which was solved in May 2004