We have studied the ground state DOS and band structure of bulk W based on density functional theory (DFT). We have also analyzed the momentum (q)-dependent loss function, dielectric constant and optical conductivity (OC) within random-phase approximation (RPA). The loss function is plotted in the energy range 0-55 eV. The energy-loss function spectrum shows four prominent peaks, the two lower peaks below and the other two higher peaks are above 30 eV. The different nature of peaks depends on the momentum transfer q. The peak caused by inter-band transition shows much less pronounced dispersion. From the dielectric function curve we have predicted the Plasmon excitation at around 1.75 eV and calculated the corresponding plasma frequency (ωp)=26.585x1014 s-1 underestimated by the experimental value.