In the Jianshan iron deposit, minerals of a complete grossular andradite series are developed and closely related to mineralization. This article deals with occurrence, physical and optical properties, chemical compositions, assem- blages and genetic conditions of these minerals. From altered granite to exo- contoot zone grossular gradual changes into andradite, and accordingly their physical and optical properties change regularly. Andradite is closely associated with magnetite mineralization and occurs in the exocontact zone whereas grossular is closely associated with molybdenite mineralization and occurs in altered granite zone.