Abstract Compounds YSr 2−xCa xV 3O 9−y have an orthorhombic symmetry. XPS results show that the vanadium ions exist in the mixing valence in the system. Temperature dependence of magnetic susceptibility represents the Curie-Weiss law. The valence state of vanadium obviously affects the magnetic properties of YSr 2−xCa xV 3O 9−y. The system exhibits a paramagnetic behavior from 300K to 1073K.