Abstract: Abstract: Natural biological materials generally have a perfect macro and micro compound structure. Animal's teeth, claws and bones have formed the optimized geometry with excellent mechanical properties after a long period of evolution, and have occupied an important position in the field of engineering bionics. Teeth are an integral part of the predation process of vertebrates, which use their teeth to break prey down into small pieces, and remove the inedible parts of the prey. Bull shark is an animal with great bite force, and its teeth structure is one of the main reasons for its bite force. Taking bull shark's maxillary and mandibular teeth as the research object, the microstructure of bull shark teeth was observed by using scanning electron microscope (SEM), the elementary composition of bull shark teeth was observed by using energy disperse spectroscopy (EDS), and the friction and wear behavior of the bull shark teeth was investigated systematically in this paper. The wear resistance of the bull shark teeth was estimated by a wear tester. Experimental results showed that enamel layer was a compact structure formed by strip fiber bundles, and the dentin was a porous structure, which holes were in the range of 3-20 μm with an irregular arrangement, and could improve the bonding strength. Compared with the dentin, the contents of calcium (Ca) and fluorine (F) in the bull shark teeth enamel were much higher, and these 2 types of elements could help teeth have better acid resistance and hardness. The surface roughness of the polished teeth sample, which contacted with Si3N4 ceramic ball, was small at first. Therefore, the enamel of bull shark's maxillary and mandibular teeth had a low initial friction coefficient. After a period of time, due to fatigue damage in the enamel surface and brittle cracking, the friction coefficient rapidly increased in the enamel material with the peeling of teeth. The friction coefficient of the 2 different samples changed with time and presented different trends. The friction coefficient of the maxillary teeth showed a rapid increase after 60 s, while the time for the mandibular teeth was 35 s. The flake wear debris peeled off in the surface of bull shark enamel, and the surface was attached to a lot of fine abrasive particles. The maxillary teeth wear volume was 1.72×107 μm3, and the wear debris peeling was mainly caused by fatigue wear; the mandibular teeth presented obvious cracking phenomenon, and the wear volume was 2.11×107 μm3, higher than the maxillary teeth. The friction and wear experimental results showed that the abrasion resistance of maxillary teeth was better than that of mandibular teeth because the maxillary teeth are responsible for cutting their prey, but the mandibular teeth are only responsible for piercing prey in the process of long-term predation. This paper provides a reference for the design of a new type of cutlery and the experiment data and theoretical basis for the study of the tribology properties of animal teeth in the future by observing the microstructure and testing the friction properties.