Non-depolarizing muscle relaxant; d-tubocurarine was introduced clinically in 1942. Thereafter depolarizing muscle relaxant; succinylcholine was introduced in 1951. Those muscle relaxants were highly contributed in modern anesthesia practice today. But, since many years ago complications of succinylcholine were reported clearly so many anesthesia practice. Complications were such as ventricular arrythmia(cardiac arrest), fasciculation, hyperkalemia, muscle pain, elevation of intragastric, intraocular & intracranial pressure, prolonged apnea, generalized muscle clonus, masseter muscle rigidity and malignant hyperthermia etc. Succinylcholine was still used in clinical practice despite of many complications reported as long as more than 45 years. Finally, FDA(USA) decleared the routine use of succinylcholine was contraindicated in children and adolescents. Many textbooks of anesthesiology shows that use of succinylcholine was contraindicated in children and adolescents those were published recently since 1994. What is the current status of succinylcholine in despite of changing current concept of succinylcholine use in Korea? Succinylcholine is still inadvertently used in Korea over 79% of resident training hospital. Intravenous dantrolene reserve was only one hospital(1.4%). Undoubtedly, amazing things were going on in Korea. Seventeen cases of malignant hyperthermia had been reported from 1971 to 1996 on Korean medical journals. It's mortality was 70.6%. Not only the reported malignant hyperthermia, there are many cardiac arrest during anesthesia reported on Korean medical journals. Etiological analysis of cardiac arrest was reviewed some of them, there are certain numbers of cardiac arrest cases confirmed by succinylcholine was guilty. What is the counterplan? Change the current concept of succinylcholine is important. Conclusions ; 1. Non-depolarizing mucle relaxant should be used for intubation