The objective of this study was to develop an automated rice transplanting system in paddy fields. It is necessary to determine the precise position and direction to control the vehicle automatically in paddy fields. In this paper, the position of the rice transplanter was determined by real-time kinematic GPS (RTKGPS). The inclination of the rice transplanter influenced the RTKGPS position data, including time delay because the GPS antenna was set at a 2 m height from the ground. The correction can be performed by measuring the roll, the pitch and the yaw angles of the rice transplanter. The yaw angle was measured using a fiber optic gyro (FOG) sensor and the roll and pitch angles were measured using an inclination-measuring apparatus consisting of 3 FOG sensors and 3 accelerometers. When the rice transplanter was driven automatically along the desired straight path, the deviation from the desired straight path was less than 10 cm.