Adopting a noise-initiation mode of stimulated brillouin scattering (SBS), optical limiting effect are numerically simulated by using 7 ns, 1064 nm, Nd∶YAG laser pulses within CCl4 liquid in SBS process. When the pump energies are low, the nonlinear medium can be optical transparent. When pump energies are higher than the threshold of stimulated Brillouin scattering, the peak powers of nanosecond laser pulses are limited, pulses are narrowed and the energies tend to saturated. This means the optical limiting has both power limiting and energy limiting characteristics. The relationships of optical limiting effect such as output peak power, output energy, transmissivity and pulse compression ratio versus pump energy are investigated by a theoretical model. The experimental results of above optical limiting effects were given. In authors' experimental regime, results were in good agreement with the conclusions predicted by theoretical simulations.