Abstract:Does the theory of special relativity have its experimental foundation? Can it be proved by experiments? Does the relativity about the expansion of time and space contraction exist? Is the Lorentz transformation relative or absolute? These questions are discussed and analysed in this article.The following conclusion is drawn:By now, no experiments which are in accordance with Einstern's requirements can be found in the literature, these experiments can at best prove time expansion exists and is absolute.They cannot prove the correctness of the relativity at all.