An electronic device with a message encryption function includes a configure interface module for setting an encryption code, a storage module, an encryption module, and a message processing module. The message processing module is electrically connected to the configure interface module, the storage module and the encryption module for receiving or sending a message, accessing the encryption code from the configure interface module, and transmitting the message and the encryption code to the encryption module. The encryption module encrypts the message with the encryption code so as to generate an encrypted message and then transmits the encrypted message to the message processing module. The message processing module stores the encrypted message in the storage module.