Improving the service quality of hospital health center is crucial for increasing its competitiveness. After sending questionnaires to four hospital health centers in Hangzhou, we use regression analysis to research five encounter factors' influence on service encounter quality, including doctors' professional competence, doctors' attitude, guidance nurses' attitude, receptionists' attitude and service environment. Besides, we analyze different perceptions of encounter factors caused by the differences in health examiners' personal attributes. As a result, guidance nurses' attitude is the most principal influencing factor of service encounter quality. Finally, we propose some advice to hospital supervisors.