Abstract: Integrated radar and communication system can make full use of radar equipment and play an important role in achievement of multi-functional integration of electronic equipment. A kind of integrated radar and communication signal is proposed based on the relationship between chirp-rate of chirp signal and the order of fractional Fourier transform. Its main carrier adopts the unique chirp signal to implement radar function, while communication information is modulated by the subcarrier with communication code keying chirp-rate chirp signal. The superposition of the main carrier and the subcarrier enables the signal to transmit multi-binary information by single signal without degrading radar's performance. Finally, simulations demonstrate that the proposed signal has an advantage of high robustness.