Sodiumlignosulphonate was added to sulphate resisting cement as chemical additive to modify its physical and chemical properties for conditioning hazardous and radioactive wastes for long term disposal. The effect of some organic and inorganic chemicals on sulphate resisting cement was investigated. The physical properties such as density, porosity percent and absorption percent for all the studied samples as well as the compressive strength values and the leaching properties were also determined. The thermal stability and the radiation stability were also investigated.