In this talk, I will present two different codings of multitype trees with edge lengths based on their breadth first search algorithm. When applied to multitype branching trees, the first one allows us to make explicit the law of some functionals such as the total length of the branches of each type or the total population size up to extinction. The second coding allows us to obtain a representation of continuous time multitype branching processes as a time change of some class of multi-indexed Lévy processes. Then, using this transformation and describing the law of the first passage time process of such multi-indexed Lévy processes, we obtain some information on the extinction probability of multitype branching processes.