Service sector has dominated global economy.  Services science is emerging, which aims at studying systematically service by using formal and interdisciplinary methods.   The background of service science emerging was introduced to disclose the necessity and urgency of this field.  The development of service science was briefly reviewed.  Service, which is a new academic discipline, was discussed in detail, including the definition, characteristics, partition and classification.  The conceptualization and objectives were further elaborated.  Core problems that service science focuses on are proposed to tell researchers which problems are more worth investigating.