Purpose: To clarify how the introduction of a two-shift work at （intensive care unit; ICU） of A-Hospital affected nurse burnout and job satisfaction. Method: We conducted a Mann-Whitney U test and Spearman’s rank correlation analysis on the relationship between nurse burnout, job satisfaction, and attributes of the nurse before and after the introduction of a two-shift work system in 36 nurses working at the ICU of A-Hospital. Result: There were no significant differences in all subscales of burnout before and after the introduction of the two-shift system, and the values after the introduction of the two-shift system were significantly higher for all factors of job satisfaction than before. After the introduction of the two-shift system, a moderate negative correlation （r = -0.50） was found with “workable work environment” and age, and a moderate negative correlation （r = -0.54） was found with all years of clinical experience. Discussion and Conclusion: The introduction of the two-shift work system suggested that it could improve job satisfaction. In addition, it is necessary to give sufficient explanation and consideration to nurses with many years of experience when introducing a two-shift work system in ICUs.