The effect of some factors on the susceptibility of eleven soybean genotypes against Tetranychus urticae infestation during two successive seasons 2012 and 2013 was evaluated. The highest population density, in  terms or motile and egg stages, was recorded on the genotype H15L27  (4980.3  and 3670) and (2898  and 2248);  while the lowest was for the genotype H 19L96 (2146 and 1533.3) and ( 1573.3 and 1309). respectively for the two years. The lowest in tested genotypes were characterized by thickness of the upper and lower epidermis (17.67  and 14.28 µ). as well as palisade tissue and the thinness of spongy tissues (90.53 and 51.86 µ), respectively. Mite population density was positively correlated with leaves nitrogen and potassium contents; while negatively correlated with phosphrous. The predatorys, Phytoseiulus persimilis  and the thrips, Scolothrips sexmaculatus, populations were recorded at the lowest density or T urticae and vice versa. The susceptibility of soybean genotypes to the spider mite infestation was governed by leaf phytochemical components and histological structure of its surfaces and the presence of natural enemies. These results could be involved in breeding programme cultivated to improve future integrated pest management of soybean in  Egypt.