Abstract: AHDEB, the first oilfield which has been constructed productivity by CNPC successfully in Iraq, is developed by line pattern of horizontal wells. The prediction of natural flow ceasing time is an important basis for rational production proration of individual wells and the determination of production construction capacity of this field. Study on ceasing conditions of natural flow has been conducted previously, but no methods is available to predict ceasing time of natural flow. In this paper, 3 kinds of methods are applied to predict the ceasing time of natural flow, namely, minimum wellhead pressure method, minimum bottom hole flowing pressure method and minimum reservoir ressure method. Field application shows minimum well head tubing pressure prediction result is most close to the practical situation. The study is of great instructive significance for the production management in the initial stage.