The present invention provides a method, a subscriber server and a mobility management entity for determining a serving node of a short message service. After receiving a location update request sent by an MME, an HSS/HLR determines services subscribed to by a subscriber. When determining that the subscriber has not subscribed to a CS domain service or there is only an SMS service in CS domain services subscribed to by the subscriber, the HSS/HLR registers the MME as a serving node that provides the SMS service for the subscriber.