The microstructures of conch shell were observed with scanning electronic microscope (SEM),and a kind of inclined-cross microstructure of aragonite sheets was found. The maximal pull-out force of the inclined-cross microstructure was analyzed based on its representative model and compared with that of a conventional0°-structure. The experimental result indicates that the maximal pull-out force of the inclined-cross microstructure is markedly larger than that of the 0 °-structure.