A stereo image data transmitting and receiving method, comprising: a first transmission-mode-information receiving step of receiving, by a transmission-mode-information receiving section of a transmitting apparatus, via a digital interface, transmission mode information transmitted from a transmission-mode-information transmitting section of a receiving apparatus, the transmission mode information indicating transmission modes for stereo image data that can be supported by the receiving apparatus; a transmission mode selecting step of selecting, by a transmission mode selecting section of the transmitting apparatus, a predetermined transmission mode from among the transmission modes for stereo image that can be supported by the receiving apparatus, on the basis of the transmission mode information received in the transmission-mode-information receiving step; a data transmitting step of transmitting, by a data transmitting section of the transmitting apparatus, in the transmission mode selected in the transmission mode selecting step, to the receiving apparatus, stereo image data for displaying a stereoscopic image, by differential signals on a plurality of channels via the digital interface; a transmission-mode-information transmitting step of transmitting, by a transmission-mode-information transmitting section of the transmitting apparatus, transmission mode information on the stereo image data transmitted in the data transmitting step, to the receiving apparatus via the digital interface, by inserting the transmission mode information in a blanking period of the stereo image data; a data receiving step of receiving, by a data receiving section of the receiving apparatus, stereo image data for displaying a stereoscopic image, from the transmitting apparatus by said differential signals on a plurality of channels via said digital interface; a second transmission-mode-information receiving step of receiving, by a transmission-mode-information receiving section of the receiving apparatus, transmission mode information on the stereo image data received in the data receiving step, from the transmitting apparatus, by extracting the transmission mode information from a blanking period of the stereo image data received in the data receiving step; and a data processing step of processing, by a data processing section of the receiving apparatus, the stereo image data received in the data receiving step, on the basis of the transmission mode information received in the transmission-mode-information receiving step, to generate left eye image data and right eye image data. a first transmission-mode-information receiving step of receiving, by a transmission-mode-information receiving section of a transmitting apparatus, via a digital interface, transmission mode information transmitted from a transmission-mode-information transmitting section of a receiving apparatus, the transmission mode information indicating transmission modes for stereo image data that can be supported by the receiving apparatus; a transmission mode selecting step of selecting, by a transmission mode selecting section of the transmitting apparatus, a predetermined transmission mode from among the transmission modes for stereo image that can be supported by the receiving apparatus, on the basis of the transmission mode information received in the transmission-mode-information receiving step; a data transmitting step of transmitting, by a data transmitting section of the transmitting apparatus, in the transmission mode selected in the transmission mode selecting step, to the receiving apparatus, stereo image data for displaying a stereoscopic image, by differential signals on a plurality of channels via the digital interface; a transmission-mode-information transmitting step of transmitting, by a transmission-mode-information transmitting section of the transmitting apparatus, transmission mode information on the stereo image data transmitted in the data transmitting step, to the receiving apparatus via the digital interface, by inserting the transmission mode information in a blanking period of the stereo image data; a data receiving step of receiving, by a data receiving section of the receiving apparatus, stereo image data for displaying a stereoscopic image, from the transmitting apparatus by said differential signals on a plurality of channels via said digital interface; a second transmission-mode-information receiving step of receiving, by a transmission-mode-information receiving section of the receiving apparatus, transmission mode information on the stereo image data received in the data receiving step, from the transmitting apparatus, by extracting the transmission mode information from a blanking period of the stereo image data received in the data receiving step; and a data processing step of processing, by a data processing section of the receiving apparatus, the stereo image data received in the data receiving step, on the basis of the transmission mode information received in the transmission-mode-information receiving step, to generate left eye image data and right eye image data.