The present invention provides a method and system for processing sessions and messages, and relates to the network session technology. The method includes: the initiator sends a session request to the recipient service server; and the recipient service server generates session invitation information according to the received session request when detecting that a recipient is offline, and sends the session invitation information to the recipient. Therefore, the recipient knows the session invitation information received in the offline period even when the initiator provides no session content; and the method can be implemented in diversified ways, thus enriching the service experience of the user.