Because of biominerals,controlled morphology and unique properties,biominerals become the idea headspring for making organic-inorganic hybrid composite with new patterns.The preferred orientation phenomena of minerals on bioorganics are frequently observed in organisms,this can make the material′s performances become better,the human bone is a good example.By now,in most of the prepared nano-composites,the nano-particles dispersed randomly in polymer matrix.In this paper,magnetic/chitosan nano-composite in the magnetic environment was prepared via in-situ precipitation.From the XRD,TEM testing results,it can be concluded that nano magnetite particles arranged orderly in the chitosan matrix,the average diameter of the particles is about 11.3 nm.This provides a new method for preparing three-dimensional magnetic biomaterial,and has broad potential application to the bone repair field.