This paper focuses mainly on Bit Error Rate(BER) and Signal to Noise Ratio(SNR).To analyse the system's performance probability of error plays a major role. Each modulation technique has its own performance while dealing with signals corrupted with noise. This paper describes the comparative analysis of basic M-ary Phase Shift Keying modulation schemes like BPSK, QPSK,8-PSK and 16-PSK. It gives that increasing of M results in increase of Bit Error Rate. Here BER and SNR are the key factors to evaluate the performance of M-ary PSK modulation system. The BER curves for MPSK modulation obtained after simulation are compared with theoretical curves for M=2,4,8, and 16.