This research was done to study some hydraulic properties of  dripper discharge, uniformity and manufacture variation, for five kinds of drippers used in Yemen. A drip irrigation network was constructed in the Faculty of Agriculture - Sana'a University during the period from 2/10 until  25/11/2010. This network included three different lengths for lateral  lines ( 20, 30, 50 meter)  with five kinds of drippers (drippers with pressure valve and drippers without pressure valve) to study the affect of lateral line length and dripper kind on discharge, and dripper uniformity under three working pressures ( 50, 65, 75 kPa ) . The results of this study are as follow: Dripper discharge was increased with pressure increase and the discharge decreased with drippers line lengths. Italian dripper without pressure valve "Turbo" achieved maximum discharge of 3.800 liter/hour. Jordanian dripper with pressure valve "Nein" achieved minimum discharge of 3.075 liter/hour.  Manufacturer factor C_V decreased with pressure increase for all drippers. The dripper without pressure valve achieved minimum difference in manufacturer factor. Italian dripper with pressure valve "Turbo" recorded maximum C_V with average 0.014, and Italian dripper without pressure valve "Turbo" recorded minimum C_V with average 0.012. The Jordanian dripper with pressure valve "Nein" recorded maximum C_V with average 0.020, and Jordanian dripper without pressure valve "Nein" recorded minimum C_V with average 0.013 and all of them were good. Italian dripper without pressure valve "Turbo" had maximum uniformity of 96.408%, but the Jordanian drippers with pressure valve "Nein" had minimum uniformity of 92.957%, and line length of 20 meter had maximum uniformity. Pressure was 75 kPa.