This is a prospective dose-finding study of sugammadex for conventional reversal of rocuronium-induced neuromuscular blockade in children under two years of age. This study will explore 50% effective dose and 95% effective dose of sugammadex for reversal of neuromuscular blockade in less than two minutes under biased coin up-and-down method.

The investigators are planning to enroll 33 patients to obtain data. The starting dose of sugammadex will be 0.5mg/kg. When the dose for a patient was not effective, the dose for next patient will be increased by 0.5mg/kg. When the dose was effective, the dose for next patient will be decreased by 0.5mg/kg or maintained, with a 1:1 of allocation ratio.

The investigators will also monitor incidence of any adverse events including residual blockade to evaluate safety of sugammadex in children younger than two years old.

Inclusion Criteria:

• Childern younger than 2 years old who are scheduled to undergo surgery under general anesthesia
• American Society of Anesthesiologists Physical Status 1 or 2

Exclusion Criteria:

• History of hypersensitivity to rocuronium or any anesthetics
• Presence of cardiovascular or genitourinary disease
• Presence of severe renal dysfunction or in need of dialysis
• Presence of severe hepatic dysfunction or coagualtion disorder
• Current state of administration of neuromuscular blocking agent on admission to operating room
• Concurrent use of any medications that affect the activity of neuromuscular blocking agents
• History of malignant hyperthermia
• Refusal to enroll in the study by one or more parents
• Presence of any other reasons that investigator regards inappropriate to enroll in the study.