A field study was conducted at the Agricultural Research Station, affiliated to the College of Agriculture, located in Al-Buetha area, Al-Ramadi District, - center of Anbar Province. During the autumn season in 2022, in a sandy clay loam soil. This study was conducted to investigate the effect of field use of drip irrigation system and its impact on the adopted evaluation criteria before and after planting. To determine the effect of the drip irrigation system duration of using on its field performance. Before planting, the irrigation system was evaluated in the field by conducting tests at three different operating pressures, namely 0.3,0.5 and 0.7 bar to determine the actual discharge of the emitters closed to their design discharge. The evaluation criteria in this study were emitters discharge rate, uniformity coefficient, emission uniformity, discharge variation ratios. The results indicated that the operating pressure of 0.5 bar was the best among the selected pressures, where gave the highest actual discharge of 7.87 L h-1 which closed to its design discharge i.e., 8 Lh-1. Additionally, the highest coefficient of uniformity was achieved, reaching 96.39%, along with the highest emission uniformity of 95.93%. The lowest variation in discharge between emitters was recorded at 9.58%. Consequently, this pressure (0.5 bar) was adopted for operating the drip irrigation system throughout the study period.