A moving body transmitter and receiver axis adjusting system includes a radar system mounted on a moving body and having a scanning area of 10.degree. and a detection area of 8.degree. in each of the left and right directions, and carrying out auto aiming to adjust the detection area in left and right directions inside the scanning area so that an object detection axis that is the center of the detection area coincides with a reference reflecting body placed on a vehicle center line. When a deviation between the object detection axis and the reference reflecting body exceeds 2.degree., adjustment cannot be completed only by auto aiming. In this case, the angle at which the radar system is mounted on the vehicle body is manually adjusted in the left and right directions so that the object detection axis overlaps the vehicle center line.