Abstract: Sandstone matrix acidizing is the effective traditional technology to increase oil well output, but there are a certain disadvantages, such as hydrofluoric acid (HF) dissolute the clay too fast, the dissolution time is too short to penetrate formations, and the reaction of the hydrofluoric acid and clay minerals will cause secondary precipitation and finally damage formation. However,retarded acid system has added new vigor for this technology, which is optimized for Paleogene Zhuhai reservoir of Panyu Oilfield by the large number of acid test, and separated layer acidizing technology was adopted according to in-situ tests. It is proved that the optimized acidization system is very successful and provides a strong support for the stable oil and gas production in the region.