Cinnamyl alcohol dehydrogenase (CAD) catalyzes cinnamyl aldehydes into cinnamyl alcohols, the final step in lignin biosynthesis. In this studied the purification, identification and characterization of a new cinnamyl alcohol dehydrogenase gene isolated from Citrus platymamma hort. Ex Tanaka. We expressed CAD potential gene in E.coli and then characterized its features in variety of specificity aldehydes substrates. The recombinant CAD protein was shown highest efficiently catalytic toward cinnamyl and coniferyl aldehydes and the shown lowest efficiently catalytic toward sinapyl aldehydes. We used a new improved analytical HPLC method in CAD enzymatic assay for fast and accurately measurement in various aldehydes substrates. In conclusion, our studies indicated the enzymatic activity of cDNA cloned CAD protein from Citrus platymamma hort. Ex Tanaka.