The chitin abstracted from silkworm chrysalis was subjected to toxicological study including: (1)systematic toxicological test, (2)pyretogenic test, (3)primary cutaneous irritative test, (4)intradermal injection test, (5)cutaneous allergic test. (6)conjunctival irritative test, (7)hemolysis test, (8)bacterial toxicity test, (9)dominant lethal test, and (10)mutagenetictest. The results showed that chitin is atoxic, non-irritative, non-allergenic, nonpyretogenic, non-hemolytic, non-mutagenic, and non-lethal mutagenic. Therefore, chitin is a compatible biomaterial for implanting into the tissue.