Abstract: A 6 degree of freedom electromagnetic tracking system for virtual reality applications is described. The system employs a magnetic transmitter and a magnetic sensor, both with 3 orthogonal axes. A direct current pulse sequence drives the 3 axes of the transmitter to emit one after another. The sensor detects three groups of transmitted signals as well as the magnetic field of the environment, from which the position and orientation of the sensor with respect to the transmitter can be determined. A controller is designed for driving the transmitter, reading the sensor data and communicating with the PC. The calculation algorithm, error analysis and hardware implementation of the tracking system are discussed in detail.