AlSin Spring spurts at the foot of coastal mountains and pours in The Mediterranean sea near Arab-Almulk village. Presently, spring water used for drinking, irrigation and industry, while excess water goes to sea. Current research aims to determine the daily discharge response to daily rainfall, and to set an equation for recession discharge for predicting spring discharge and volumes of flow after definite time from the beginning of spring base flow, which allows to operate and manipulate available water resources through an optimum design of water intake from this spring. Response time of AlSin Spring between (3-5) days for average discrete daily rainfall with high intensity which caused 0.5 ~ 1.0 m3/sec increasing in spring discharge value. Yearly discharge trends to decrease with a rate of 0.0975 m3/sec between 1974 and 2016 years. While the monthly minimum discharges increase about 0.1284 m3/sec, and monthly maximums decrease about 0.0752 m3/sec between 1994 and 2016. We recommend adopting recession curve analysis to predict the optimal discharge of springs within definite periods.