E. C{fiverm ARTAN} introduced the Riemannian locally symmetric spaces, as the one whose curvature tensor is parallel. They also howe their name to the fact that for each point the geodesic reflexion is a local isometry. The aim of this note is to announce a strong rigidity result for Finsler spaces. Namely we show that a negatively curved locally symmetric (in the first above sense) Finsler space is isometric to a Riemann locally symmetric space.}