A charging monitoring method includes triggering a quota monitoring procedure for a consumption amount of an international roaming subscriber when it is determined that a service request is specific to the international roaming subscriber. The quota monitoring procedure is performed in a charging network element of an intelligent network system. The method also includes monitoring the consumption amount of the international roaming subscriber through the quota monitoring procedure to determine whether the consumption amount reaches a preset quota. If the consumption amount reaches the preset quota, the method includes rejecting the service request according to a rejection instruction returned by the charging network element. If the consumption amount does not reach the preset quota, the method includes approving the service request according to an approval instruction returned by the charging network element.