A multiphase Ge-based Ge/FeGe/FeGe2/C (Fe-Ge-C) composite is prepared through the reaction between ferrous tartrate and GeO2 at Ar/H2 atmosphere, in which the active Ge, alloying components and amorphous carbon are generated synchronically. When evaluated as an anode material for lithium ion batteries, the Fe-Ge-C anode manifests an enhanced capacity of 1095mAhg−1 at 0.1Ag−1 and with capacity retention of 890mAhg−1 at 0.5Ag−1 over 400 cycles. A good rate capacity of 465mAhg−1 at 10Ag−1 is also obtained. The synchronically formed conductive alloying components and amorphous carbon lead to the long cycle stability, and good rate capability. Furthermore, the synthetic route could be extended to the preparation of other kinds of multiphase Ge-based composites.