Self-pumped phase conjugate in Co-doped (K0.5Na)0.2(Sr0.75Ba0.25)0.9Nb2O6 crystal was demonstrated without external reflection mirrors, pumping beam and applied field. Its phase conjugation reflectivities as high as 40% were measured. The threshold power was lower than 0.02 W/cm2, The device operated by one-region four-wave mixing using the photorefractive effect with the trapezoid-cut crystal.