Soil defilement with "raw petroleum" is a standout amongst the most across the board and genuine ecological issues going up against both the industrialized and oil country like Iraq. Along these lines, the impact of "raw petroleum" on soil contamination is one of most critical subjects that review these days. The present examination expects to research "unrefined oil"effectson the mechanical and physical properties of clayey soils. The dirt examples were acquired from Al-Doura area in Baghdad city and arranged by the "Brought together Soil Grouping Framework (USCS)" as silty mud of low pliancy (CL). Research center tests were done on contaminated and unpolluted soil tests with same thickness. The dirtied tests are set up by blending the dirts with various percent of "raw petroleum", and these percent are5%, 10% and 15% by dry weight. The exploration results demonstrate a reduction in the quality of the dirt, explicit gravity, greatest dry thickness and ideal dampness content. Then again, the outcomes showed an expansion in Atterberg cutoff points and compressibility of the dirt. The outcomes demonstrated additionally an impressive increment in the estimation of combination parameters such ascoefficient of volume compressibility, pressure file and lessening in the coefficient of solidification and shear quality.