Silicon Oxycarbide (Si-O-C) composite anode materials are prepared by pyrolysis of polysiloxane containing phenyl under argon and hydrogen atmospheres, separately. They are characterized by element analysis, wide-angle powder X-ray diffraction, Raman spectroscopy for comparison with each other. It is found that the silicon oxycarbide composite anode pyrolyzed under a hydrogen atmosphere demonstrates lower irreversible capacity and larger reversible capacity which increases with temperature rising. The one pyrolyzed at 1000 ℃ shows a reversible capacity of 622 mAh/g, and first coulombic efficiency of 59%.The magnitude of the irreversible capacity is correlated with the content of oxygen, and the reversible capacity is related to the content and structure of free carbon, and also the structure of Si-O-C. It is believed that Si-O-C composite materials pyrolyzed under a hydrogen atmosphere could be promising anode materials for lithium ion batteries.