Poly-α-amino acid is a kind of biodegradable biomedical material.It is used forthe preparation of sustained drug-release device.There are some advantages of thedrug delivery devices.They can provide the therapy with side effects.The drug re-lease is maintained at a beneficial rate for a prolonged time.The polymer may bebiodegraded after the drug has been exhausted. Poly-α-amino acid is a kind of biodegradable biomedical material. It is used forthe preparation of sustained drug-release device. There are some advantages of the drug delivery devices. They can provide the therapy with side effects. Drug re-lease is is maintained at a beneficial rate for a prolonged time. The polymer may be biodegraded after the drug has been exhausted.