Transient hyperkalemia is well known to occur in man following intravenous administration of succinylcholine chloride. We studied the change of the serum potassium concentration after injection of succinylcholine in nonburn patients and electricburn patients, physical status 1 or 2 adopted by the American Society of Anesthesiologists. We compared two groups: Non-burn patient group(Group 1) as control, Electric burn patient group (Group 2) as experimental. The following results were obtained: 1) In non-burn patient group(Group 1) serum potassium concentration was slightly decreased in the 1st, 2nd, 3rd, 4th, 5th, 6th and 10th minute after succinylcholine injection compared with control, but nostatistical significance was noticed in this group. 2) In electric burn patient group (Group 2) serum potassium concentration was maximally increased compared with the controls. Statistical significance was noticed at the 2nd and 3rd minute after succinylcholine injection in this group.