Abstract: The phase properties of selective pulses in combination with PFG has been studied theoretically and experimentally.The results show that:for symmetric and antisymmetric shaped pulses, by using selective single PFG spin-echo(SPFGSE) and selective double PFG spin-echo (DPFGSE), pure in-phase magnetization can be obtained in their whole excitation bandwidth.However, for other shaped pulses, the magnetization without phase distortions can only be obtained by using DPFGSE.Moreover, using doubly-selective SPFGSE, neither symmetric (orantisy mmetric) nor non-symmetric shaped pulses can provide pure in-phase magnetization.

Key words: NMR, PFG, Shaped pulse, Phase property