The effective atomic numbers and electron densities of few chemical explosives (CW), viz., Trinitrotoluene (TNT), Trinitrophenylmethylnitramine (Tetryl),Pentaerythritoltetranitrate (PETN), Ciklotrimetilentrinitramin (RDX), Picrylchloride (PC), Nitroglycerin (NG) and Octogene (OG) have been calculated for total and partial photon interactions by the direct method in the wide energy range of 1 KeV-100 GeV using WinXCOM. The values of these parameters have been found to change with energy and composition of the chemical explosives (CW).The variations of effective atomic number and electron density with energy are shown graphically for all photon interactions. The variation of photon mass attenuation coefficients with energy are shown graphically only for total photon interaction. The variation of effective atomic number Zeff and electron densities Nel is due to the variations in the dominance of different interaction processes in that particular energy region.