Lumbricus is in use in Korean medicine. The Korean medical doctors use Lumbricus for removing heat(淸熱), relieving muscle spasm(鎭痙), ca1ming the liver(平肝), etc. We investigated toxicity, poisoning symptoms, poisoning treatment and prevention against poisoning of Lumbricus. The results were summarized as follows: 1.The main ingredients of poisoning are terrestro lumbrolysin, lumbritin, terrestro-lumbrolysin, lumbrofebrine, etc. The ingredients of poisoning from Lumbricus mainly can cause hypersensitive efflorescense and shock for hypersensitive reactions. And these can cause headache, dizziness, stomachache, tachycardia, dyspnea. etc for poisoning reaction. 2. The representative methods of poisoning treatment in western medicine are washing out the stomach, administering toxicide, supplies of grape sugar and symptomatic treatment, etc. 3.The representative methods of poisoning treatment in Korean medicine take advantage of herbs, such as salt water, green onion, Phaseoli Radiati Semen(綠豆), Glycyrrhizae Radix(甘草), etc. And Korean medical doctors should meet symptoms as patients call for attention. 4. In order to prevent against poisoning of Lumbricus, the patients should keep usage, dosage and notes.