Hydroxyapatite/collagen (HA/COL) composites were prepared using coprecipitation and in-situ synthesis methods. All these processes yielded nanosize poorly crystallized hydroxyapatite/collagen composites. The low temperature in situ formed composites showed some features of natural bone in phase composition, crystal size and crystallinity. Compare with the composite prepared by coprecipitation synthesis, the composite resulted from a low temperature in situ synthesis method showed better homogeneity and mechanical properties. It is confirmed that the low temperature in situ synthesis method was an effective way to obtain biomimetic nanoHA/COL composites with good homogeneity and mechanical properties.