Abstract: The uniform porosity depth function drawing up on observed data does not express the compaction history of beds because different clastic beds are different in lithology and compaction process in a well or an identical region.The original porosity lied on clastic size and lithofacies so that the original porosity of a sort clastic bed can be considered as the same,but the compaction process could be different from each other.For the sake of reliability of decompaction correction,this paper provides a method of delaminated decompaction correction.First,beds in a well or an identical region are delaminated into some "compaction unit beds" based on their lithology,age,compaction process and so on.Then,the respective porosity depth function which expresses each delaminated "compaction unit bed" needs to be found.The original porosity in the porosity depth function could be determined by modeling sediments.The "compaction model" of delaminated "compaction unit bed" in a well or an identical region could be different or same but it should be reasonable to express their compaction process.And last,using the back strip method computes the paleao thickness and original thickness based on "conversation law of solid thickness of beds".