Simulation of the neutral beam emission spectroscopy (BES) is very important for the development of spectroscopic diagnostics based on neutral beam injection in the HL-2A tokamak. The effective beam emission coefficient and the effective stopping coefficient are calculated by utilizing the ADAS database (Atomic Data and Analysis Structure, 1998). Dependence of the beam emission intensity on plasma and neutral beam parameters are analyzed, and the intensity profiles of the beam emission spectra are obtained under different neutral beam energies, plasma densities and temperature profiles. About 50% of the neutral beam particles can penetrate through the plasma core when the plasma density and temperature are of 2×1013 cm-3 and 1 keV, respectively. The 2-D BES intensity profiles across the beam line are obtained and it peaks around r/a=0.6.