The self-pulsation behavior of the phase-conjugated light is studied experimentally in a semilinear self-pumped phase conjugator, which contains two BaTiO₃ crystals (one of them operates in total-internal-reflection self-pumped phase conjugator and is used as retro-reflector in this semilinear self-pumped phase conjugator). The frequency f of the pulsation is related to the incident power I₀by f∝I₀^1.43. The lasting time of the phase-conjugated light is found to be approximately inversely proportional to I₀. The dynamic spatial structure of fanning light is observed and which is responsible for the pulsation of the phase-conjugated light in the semilinear self-pumped phase conjugator.