Abstract: It is important to understand the microstructure, morphology, connection, spatial distribution and mineral constitution in vivo of bone of common carp (Cyprinus carpio) for its breeding, behavior research and fish processing. X-ray microscopic CT technology (micro CT) does not destroy the samples and is easy for bio-assay to measure the structure parameters of arbitrary shape. Thus, we apply micro CT to scan common carp′s bone and find that: vertebrae are joined with head and tail; pectoral fin is located behind head; dorsal fin, ventral fin and caudal fin are separated from vertebrae; ventral fin has higher while head has lower BV/TV and Tb.Th; head has higher BS/BV, Tb.N and Tb.Sp; dorsal bone has higher bone mineral content, bone density (BMD), tissue mineral content, while abdomen has higher bone volume fraction (BVF), next are pectoral fin, dorsal fin, head and tail. Dorsal fin and ventral fin have higher Tb.Th and mineral content, which may be caused by movement of common carp, and head′s higher BS/BV, Tb.N and Tb.Sp may be related with head′s complex structure.