Two field experiments were carried out in Sakha Agricultural Research Station, Kafr el-Shiekh Governorate, to determine the most suitable irrigation frequencies and quantities, for Snap bean and Squash, grown under drip irrigation system. The irrigation intervals of snap bean were irrigation every 4, 8, 12 and 16 days, where the irrigation intervals of Squash were, irrigation every 2, 4, 6 and 8 days.  Irrigation quantities were 0.8 and  1.0 evaporation ( Ep ), for both snap bean and squash,  based on pan evaporation. The obtained results are summarized in: 1-snap bean Irrigation water intervals significantly affected number of pods/plant, where 4 days interval recorded the highest mean (9.7). No significant differences were found between irrigation water quantities treatment means in this trait. The highest value was obtained with the treatment of 4 days interval with irrigation water quantity of 1.0 Ep . Irrigation intervals significantly affected pods dry weight/plant , where 4 days interval treatment mean represents 157.5% of that of 16 days interval treatment mean . Irrigation water quantities didn't significantly affect pods dry weight under the studied conditions. Irrigation intervals significantly affected 100 seeds weight of snap bean , where, 8, 12, and 16 days interval treatment means were 91.5, 85.6 and 83.9%of that obtained with 4 days interval treatment mean. Both irrigation quantities and irrigation interval-irrigation quantities interaction treatments did not prove any significant effect on 100 seeds dry weight . The highest seed yield resulted from irrigation interval of 4 days treatment, 1.0 Ep treatment and from 4 days interval + 1.0 EP . Raising irrigation interval from 4 to 16 days decreased W.Ut.E of snap bean by 45.8% . Irrigation interval of 8 days or above was unsuitable for snap bean plant under drip irrigation system, where,  water utilization efficiency was decreased with increasing irrigation water quantities from 0.8 to 1.0 Ep, comparing to irrigation interval of 4 days. Irrigation intervals-irrigation water quantities interaction significantly affected  W.Ut.E of snap bean  yield. The highest W.Ut.E values (0.689 kg/ m³ ) were recorded under the short period of irrigation intervals(4 days) with irrigation quantities expressed as 1.0Ep. 2-squash Irrigation interval treatments affected squash fruit length, the highest value( 12.5 cm )  was obtained with the irrigation interval of  2 days. Squash fruit diameter took the adversely trend of fruit length, as affected by irrigation water interval under the study. Irrigation interval – irrigation water quantities interaction significantly affected squash fruit diameter, where, the highest fruit diameter was obtained with 8 days interval + 0.8 Ep. Irrigation intervals treatments had a highly significant effect on squash fruit yield, where, the highest yield ( 799.596 kg/fed). Was obtained with irrigation interval 2 days treatment. Raising irrigation interval from 2 to 8 days decreased W.Ut.E of squash by 70.8%. Increasing W.Ut.E with increasing   the amount of applied water meaningfully  that the applied water quantities for yield is not enough for better growth. Irrigation intervals-irrigation water quantities interaction significantly affected  W.Ut.E of squash yield. The highest W.Ut.E values (1.582 kg/m³) were recorded under the short period of irrigation intervals (2 days) with irrigation quantities expressed as 1.0Ep.