GA-treated and non-treated G2 pea cDNAs were compared using a newly developed method called cDNA representational difference analysis (cDNA-RDA), and several GA-suppressed mRNAs were found. After cloning of the larger fragments PGAS1-3 (pea GA-suppressed cDNA 1-3), they were demonstrated to be expressed only in pea tissue not treated with GA3 through Northern analysis. Compared with subtractive hybridization and differential display techniques, this method not only can be easily manipulated but also has a relatively low rate of false positive and is highly repetitive. It is the major progress in molecular cloning techniques.