Processing bone graft materials that mimic the chemical composition and structure of natural bone is a good option for the treatment of bone defects. This investigation reports a processing condition for the in situ formation of recombinant humanlike collagen-hydroxyapatite (CHA) nanohybrid with chemical composition and crystal structure quite similar to natural bone through bionic approach. The processed CHA was characterized by various physicochemical methods and the results suggested that HA crystals are nucleated on the collagen domain with an average size of 32 nm, relatively similar to that of biological apatite. The CHA has enhanced bioresorption than HA and mimics the natural bone in composition and structure; thereby it may be considered for bone applications. © 2006 American Institute of Physics.