In light of the competitions of different medical services and the National Health Insurance¡¦s patient-oriented goal, the quality of medical care in the emergency room has been a top priory for improvement in many major medical centers. The purpose of this research is to evaluate the differences of medical quality after adjustment of physician manpower in three emergency departments of three separate hospitals. We will attempt to suggest ways to improve medical quality and make good use of medical resources. This is a retrospective survey using data from three emergency departments of three separate hospitals. The date ranged from March to April of 2002 and March to April of 2003. A total of 66,025 cases were gathered, minus 311 cases with incomplete data, the total valid data were 65,714 cases. The three hospitals A, B, C have 24,010 cases, 17,690 cases, and 24,014 cases, respectively. The result of this study showed that hospital A had increased the number of medical staff when comparing 2003 to 2002 data, however, the quality of care did not improve. Hospital B had increased the number of physicians on duty, decreased the waiting time for the patients, and the number of patients taken care per doctor had been increased too. However, within the 72-hour clinic follow-up patient numbers have increased. Hospital C have decreased the number of physicians on duty, but the waiting time have also decreased. The number of patients being taken care of by physicians, and 72-hour clinic follow-up are all increased. When compare the month between March and April of 2002, the highest ratio of 72-hour clinic follow-up is hospital A, followed by hospital B and C, in descending order. When compare the two study period of March and April of 2002 and 2003, waiting time and the ratio of waiting time in emergency department more than 6 hours is hospital A more than hospital C more than hospital B; the ratio of waiting time less than 2 hours is hospital C more than hospital B more than hospital A. The ratio of waiting time more than 2 hour but less than or equal to 4 hours and waiting time more than 4 hours but less than or equal to 6 hours is hospital A more than hospital B more than hospital C. This study suggests that the hospitals must establish a complete quality indicators, and must conduct periodic evaluation. At the same time, we must incorporate these indicators into our hospital information system and monitoring the effectiveness, in order to promote the quality of care.