Provided are magnetic core - ceramic shell (e.g., magnetite (Fe 3 O 4 ) core - calcium phosphate (Ca 3 (PO 4 ) 2 ) shell) nanocrystals with high crystallization degree, uniform size, and high chemical stability and a method for synthesizing the same. A core-shell structure is synthesized in a process of forming magnetite seeds corresponding to cores by the reduction of magnetite precursors and then, sequentially, coating the magnetite with Ca 3 (PO 4 ) 2 by the reduction of Ca 3 (PO 4 ) 2 precursors.
