ten Maize hybrids were evaluated in terms of their relative susceptibility to the two- spotted spider mite Tetranychus urticae Koch during two years 2004-2005 at Gharbia governorate. Population fluctuation of T. urticae on Ten Maize three-way crosses hybrids (i.e. TWC310, TWC311, TWC314, TWC321, TWC322, TWC323, TWC324, TWC327, Nefertity and TWC352), and their relation with weather factors were studies. Susceptibility of different Maize cultivars to spider mites infestation revealed significant differences in movable stages. Influence of leaf chemical components with T. urticae infestation was studied. The study showed that the maize hybrid (Nefertity) recorded the highly significant susceptible to T. urticae infestation with recording averages of 273.96 and 383.5 moving stages/ 20 leaves during the two successive seasons, respectively. Mite population reached its peak on maize during season 2004 at late of August and early September, for all tested hybrids, while in the second year it has two peaks the first in early of July and the second in early of September, for all tested hybrids. Developmental times and reproduction rate of T. urticae were studied on leaves of four maize three way crosses Nefertity, TW327, TW321 and TW310) at laboratory conditions at (28±2°C, 65±5 % RH and 16:8 L: D). Immature developmental time of T. urticae was the longest on TW310 (6.5days) followed by TW321 (6.1 days) than TW327 and Nefertity (5.6 & 6.1 days). Fecundity of T. urticae was 46.6, 36.8, 29.6 and 28.5 eggs/ female on Nefertity, TW327, TW321 and TW310, respectively. The highest net reproductive rate (Ro) was 18.63 female/ female/generation on Nefertity, and the lowest was 10.29 female/ female/ generation on TW310.