An all-solid-state passive mode-locked oscillator has the characteristics of high pulse energy and good stability. A high-power neodymium-doped yttrium vanadate (Nd:YVO4) parametric Kerr lens mode-locked os. cillator is researched, in which the parametric Kerr effect is from the cascaded second-order nonlinear effect pro. duced by light in lithium triborate(LBO). The results show that the oscillator can be self-started with a total aver. age power of 20 W, repetition rate of 79.3 MHz and pulse duration of 22 ps.