Noise and modulation response behavior in quantum dot semiconductor lasers under the influence the nonlinearity studied theoretically in this paper. The present rate equations model consists of five equations for the carriers density and one equation for photons density. The nonlinearity effect was added in two rate equations namely the photon density rate equation and the ground state rate equation. Two equationswere derived to calculate the noise and modulation response. Calculations in this paper focused on the effect of each of the nonlinear effect and carrier transport inside and outside quantum dots on the laserbehavior. The results indicate the weak effect of the nonlinearity on the behavior of the laser noise because of inability of the present formula to represent the nonlinear gain parameter. Also, results indicated the strong effect of the carriers relaxation from the wetting layer to the continuous state in comparison with other relaxation lifetimes in low energy states.