According to the results of mechanical property tests, the mechanical properties of heterogeneous composite-Patinopecten yessoensis (scallop) shells are anisotropic and related closely to the microstructure. The results of compression and three-point bending tests indicated that the compressive strength which vertical load on the shell surface was approximately 3.8 times than the parallel case. The bending strength which applied to the external of the shell was about 2.2 times than it loaded from the inner surface. Patinopecten yessoensis (scallop) shell is organic-inorganic composite and has different microstructure in different location in according to its functional requirements. Patinopecten yessoensis (scallop) shell is typical bioactive functional gradient material, and its microstructure is worthy of heterogeneous composite material parts design.