Abstract: In non-cooperative communication symbol rate of the transmitter is unknown， so the receiver has to estimate this parameter blindly from the received data. To correct the estimation error of symbol rate offset (SRO)， the symbol timing recovery loop for MPSK/MQAM is proposed in this paper， which can capture 0.5% SRO and ensure good steady performance by adjusting loop bandwidth with the help of lock detector. Besides， this paper proposes a new SRO acquisition method—scanning and it can capture 10% SRO. This conclusion is very important in noncooperative communication. Simulation results show that under different SRO the steady performance of the timing recovery loop is almost the same and the realtime demodulation loss compared to the theoretical value is less than 1dB.