A three-dimensional image system includes a monitor that displays an image signal as an image for three-dimensional observation, glasses for three-dimensional observation for observing, as a three-dimensional image, the image for three-dimensional observation displayed on a display section of the monitor, a storing section that is provided in the glasses for three-dimensional observation and stores an image parameter correction value for three-dimensional observation for correcting image parameters for three-dimensional observation for giving a cubic effect of the image for three-dimensional observation displayed on the display section, a scanning section that scans the glasses for three-dimensional observation in order to read information stored in the storing section, and a control section that performs control to set, according to a scanning result of the scanning section, the image parameter correction value for three-dimensional observation in the monitor.