Nowadays network plays a more and more important role in our daily life. In order to increase both the throughput and the error correction capability of the network, the subspace codes constructed from the rank metric codes can be used in the network. A specific type of rank metric codes, Gabidulin codes, are studied intensively in this thesis  including  similarity to Reed-Solomon codes. The derivation of some classic decoding algorithms are introduced before the fast algorithms are presented, which are the main contributions of this work.