Abstract: This paper is about automatic modulation recognition of TTC(Tracking,Telemetry and Control)signals of satellites. The modulation schemes considered are FM and PM. Two algorithms are developed. The influence of carrier frequency offset on the probability of correct decision is considered and some carrier frequency excursion estimation algorithms are used to remove the influence. According to the computer simulation experiment, it is found that the least-squares algorithm is an effective method to remove the influence of carry frequency offset and part noise in the algorithm based on standard deviation of the direct value non-line component of instantaneous phase( σ dp ), and that the probability of correct decision is up to 100% in the algorithm based on standard deviation of the direct value of instantaneous warped phase( σ dwp ),when the signal-to-noise ratio is higher than negative 6dB at the presence of 100Hz carry frequency offset.