The aim of this work is to develop a basic approach to the preparation of biologically active polymer-apatite composites with various mechanical properties. To this end, a type of hybrid materials bearing silanol groups were prepared from triethoxysilyl-terminated poly(oxyethylene) (PEG) and tetraethoxysilane (TEOS) by using the in-situ sol-gel process. The hybrid materials having different PEG contents were subjected to the biomimetic process for forming the bone-like apatite layer on/in the hybrid materials. It was found that a dense bone-like apatite layer can be prepared in an arbitrary thickness on/in the hybrid materials, indicating that the silanol groups introduced provide the effective sites for the apatite nucleation and formation. The polymer-apatite composites thus obtained are expected to have a great potential in the biomedical applications.