Calcium exists in several compounds, calcite (CaCO3), dolomite (CaMg (CO3)2), calcium oxide (CaO) and calcium chloride dihydrated (CaCl2, 2H2O). All of these calcium compounds occur in oil shale. This work consists of using some physical and reaction analytical methods to try to discernthese calcium constituents quantitatively. By the methods of this work, which are the complexometry reaction using dimethyl tetra acetic acid (EDTA), the hydrochloric acid etching reaction and dispersive X-ray diffraction, we have tracked these calcium qualities. Pure calcite and pure hydrated calcium chloride were the references used. By combining the three analytical methods and making calculations, we were able to identify calcium chlorides and free chloride in the Tarfaya oil shale. The material account of the calcium compounds mentioned in addition to calcite and dolomite was established.