A mobile phone alert system sets one or more alert conditions of a mobile phone, and sets a response message corresponding to each of the alert conditions. The system further monitors communication status of the mobile phone when the mobile phone is communicating with a contact mobile phone, determines if an alert condition occurs by determining if the communication status meets the one or more alert conditions, retrieves and sending a corresponding response message to the contact mobile phone number via a first network, in response to a determination that the alert condition occurs to the mobile phone. Additionally, the system may further search a second available network, sends the response message and a request of sending the response message to the contact mobile phone number to a service center via the second network, in response to the response message has not been sent successfully via the first network.