The invention discloses a mobile multimedia broadcast receiving chip. The receiving chip comprises a tuner and a modem, wherein the tuner tunes China mobile multimedia broadcast CMMB radio-frequency signals into CMMB baseband signals; a secret key decryption module is integrated in the receiving chip; the modem demodulates the CMMB baseband signals sent by the turner into an encrypted digital program information packet, and sends the encrypted digital program information packet to the external of the receiving chip; a first request secret key message sent from the external of the receiving chip is received, and the encrypted secret key carried by the first request secret key message is sent to the secret key decryption module; and the secret key decryption module decrypts the encrypted secret key, and replies the decrypted secret key to the external of the receiving chip through the modem. Meanwhile, the invention also discloses a mobile multimedia broadcast receiving device, a mobilemultimedia broadcast receiving method and a baseband processing chip, and the method and the device can improve integration level of the multimedia broadcasting receiving device.