An image coding method for properly handling a 3D video format including a base layer and an enhancement layer includes a video layer and a system layer. The video layer includes a step of coding an image to generate a coded stream. The system layer includes a step of multiplexing the coded stream and an identifier to generate a system stream, the identifier indicating whether or not the image has a left-right mixed format that includes a base layer and an enhancement layer and that has a left view image area and a right view image area in each picture. In the coding step, the image that includes the base layer and the enhancement layer and that has the left view image area and the right view image area in each picture is coded to generate the coded stream, when the image has the left-right mixed format.