Microneedles have broad applications in biomedical and neural measurements, drug-delivery systems, and microbiological sample analysis. Blood compatibility is required when microneedle is used in blood related field. We proposed a method to improve the blood clotting feature of silicon microneedle by silver coating. We fabricated the silicon microneedle with and without silver coating by wet etching and metal sputtering and implemented the clotting test. The clotting test results indicated that silver coating plays more important role to improve the blood compatibility of silicon microneedle than surface structure.