Abstract: cDNA-AFLP is considered as the most powerful mRNA fingerprinting technique，and it’s high reliability and powerful approach in detecting polymorphism loci. The technique can be amplified analyze many cDNA fragment of restrictied and it requires no prior sequence characterization of the target genome. Using wheat of planted variety as materials ,it was studied and detailed description of key technique of cDNA-AFLP technique,and the technique system was built.