The lattice effect and magnetic transition behaviors of (Pr1-yNdy)0.67Sr0.33MnO3 (y=0. 1/4, 2/4, 3/4, 1) samples under superposed magnetic fields (i.e. the superposed AC and DC magnetic field) were systematically studied in the temperature range from 4.2 to 330 K. The results show that the magnetic transition temperature (Curie temperature, TC) of (Pr1-yNdy)0.67Sr0.33MnO3 shifts to a lower temperature as Nd substitutes for Pr, which is related to the degree of lattice distortion. The magnetization of samples increases with the increase in applied magnetic field and the in-phase-part of the AC susceptibility decreases as the superposed DC magnetic field increases. Under superposed magnetic fields, a characteristic sharp peak of the in-phase part of the susceptibility appears near TC. For the (Pr1-yNdy)2/3Sr1/3MnO3 system, as the Nd content increases, the peak temperature of the relative variation for the in-phase part of magnetic susceptibility (EX`=△X`/X`dc) decreases, in consistent with that of the magnetoresistivity of this system. The magnetic transition behaviors under superposed magnetic fields for the manganite systems are discussed.