Abstract: GDP- D- mannose pyrophosphorylase is an enzyme ininitial committed step of As A biosynthesis,which has not been reported in Chinese jujube. In this paper,an 1086 bp open reading frame c DNA encoding GMP was cloned from ‘junzao ' by homologous gene cloning method on the basis of the homologous genes of Malus domestica,Prunus persica and Fragaria vesca,etc. in Gen Bank. The sequence was named Zj GMP( accession number KJ934995) and encoded 361 amino acids,with molecular weight 39.588 ku and theoretical isoelectric point7.12.Similarity analysis showed that the protein had highly similar to the Zj GMP of Prunus persica,Vitis vinifera,Fragaria vesca and Malus domestica with similar of 88%,87%,87% and 87% respectively; phylogenic analysis showed that GMP from jujube had a closer relationship with that from Prunus persica,Malus domestica and Fragaria vesca.