Abstract: Enhanced liquid production model is an effective way to keep steady production and enhance ultimate recovery in middle - late stage of water - flooding reservoirs. The choice of timing and indexes determination of enhanced liquid directly influence the development of late stage. Based on existing research results and a true example of other water- flooding reservoir, with comprehensive use of reservoir engineering methods such as logistic model, oil percolation dynamic curve method and the relation between injection- production ratio and formation pressure drop, the paper makes a systematic analysis on the main technical indexes such as the choice of timing, conditions, reasonable oil production rate in the middle - late stages of water- flooding reservoirs development, injection- production ratio and bottom hole flowing pressure, which provides an importance guidance for water - flooding reservoirs in the middle - late stage of development.