Recently, Wang and Xiao studied a four-dimensional competitive Lotka-Volterra system
within a deterministic environment in [11]. With
the help of numerical example they showed the existence of a chaotic attractor through the
period doubling route. In this paper, we are interested to study the dynamics of the same
model in presence of environmental driving forces. To incorporate the environmental
driving force into the deterministic system, we perturb the growth rates of each species
by white noise terms. Then we prove that the unique positive global solution exists for
the noise added system and the general p-th order moment of it is bounded
for p ≥ 1, which ensures that the solution is stochastically
bounded. It is also shown that the solution of the stochastic system is stochastically
permanent under some simple conditions. Finally , we demonstrate the noise induced
oscillation for the concerned model with the help of numerical example..