The invention discloses a method and a system for prompting border roaming of a handheld device. The method includes the steps: 1, detecting communication states of a handheld device in real time; 2, extracting base station attribution information of a handheld device linked network; 3, judging whether base station attribution is as same as handheld device number attribution, if so, performing normal communication, and otherwise executing a step 4; and 4, positioning the handheld device currently, judging whether a current position is located in the same region of the base station attribution, if so, performing normal communication, and otherwise, promoting a user that the handheld device is in a border roaming state. By the method and the system, telephone charge can be effectively saved for users in urban border regions and users frequently come and go to urban borders, prompting is performed only aiming at border roaming, prompting of all roaming situations is avoided, requirements of a part of crowd are met in a more targeted manner, and experience of another part of users is unaffected.