Abstract. In this talk I will discuss our recent work on studying the impact of modeling of the bias on accurate prediction of the large scale structure bispectrum in the presence of primordial non-Gaussianity. I will describe our theoretical prediction for the bispectrum and the comparison with N-body simulations. We use three different prescriptions for calculating the baises namely the biases obtained from excursion-set peaks, biases calculated explicitly from peak-background split and a local bias model and calculate the one-loop Lagrangian-space bispectrum in the squeezed limit using the integrated perturbation theory. Our results indicate that the scale-dependance of the quadratic and third-order bias is a crucial ingredient in accurate prediction of the bispectrum in the squeezed limit.