The relative population densities of Tetranychus urticae Koch (Acarina: Actenidida : Tetranychidae) movable stages  infesting leaves of five cucumber cultivars (Impress F1, Yaaqube, Prince 3, Madina 2 and Sahm) during 2009 and 2010 seasons was investigated at Qalyubia Governorate. The results indicated significant differences between the tested cultivars in their relative susceptibility to T. urticae infestation. In the two tested seasons the five cucumber cultivars were grouped into four groups, as the highly infested cultivars were Impress F1 and Yaaqybe while the lowest infested group included Sahm cultivar, which was characterized by somewhat the thickest layer of the upper & lower epidermis and palisade tissue and the thinnest layer of spongy tissues. While, leaves of Impress manifested approximately the thinnest layers of the upper & lower epidermis and palisade tissue) and the largest diameter of Spongy tissue. Insignificant negative correlation coefficient values were calculated between the mean abundance of T. urticae individuals infesting different cultivars and the relation of thickness of the upper & lower epidermis, and palisade tissues while the relation with the spongy layers was positive i.e., cultivars characterized by thicker layers of the previously mentioned three layers were less susceptible to this pest infestation and subsequently, infested by fewer population of the two spotted spider mite and vice versa.