A cladding pumped Yb3+-doped fiber laser operating in a hybrid Q-switched regime with a tunable repetition rate is described. By exploiting fiber nonlinearity-stimulated Brillouin scattering (SBS) process in the laser cavity, the pulses with duration of 4. 8 ns and the peak power of 8. 3 kW have been achieved. The repetition rate was stable and adjustable by the pump source.