The prepn. and x-ray structure detn. of first branched star-type polysilyllithium compd., (Me3SiMe2Si)3Si-Li, in which three silicon atoms are contained in each side chain, is reported. Thus, reaction of (Me3SiMe2Si)3Si-HgtBu with Li/hexane (ultrasonic radiation) or Li/THF gave [(Me3SiMe2Si)3Si-Li]2 (1) and (Me3SiMe2Si)3Si-Li.3THF (2) resp. The crystal structures of 1 and 2 and mol. structure calcns. of model compds. are reported.