Abstract: The soluble starch synthase gene（LrSSS）was cloned from‘Meirenhong’，a species of lotus rhizome based on reverse transcription polymerase chain RT-PCR and RACE methods with leaf as template in the present study. The full-length of LrSSS（GenBank accession number KP201636）was 4 080 bp in nucleotide containing an open reading frame of 3 696 bp which encoding 1 231 amino acid. Phylogenetic analysis showed that LrSSS had 79%，69% homolog with melon，grape respectively. LrSSS contained three typical carbohydrate domains（CBM_25）and one catalyzing domains（Glyco_transf_5）relevant to starch synthesis. The expression in different temporal and spatial of LrSSS was determined by RT-PCR method. The results was that LrSSS showed the highest expression in the last leaf，and then followed by the stalk of the penultimate leaf，the lowest expression was found in the the stalk of the last leaf. In addition，the expression of LrSSS was higher in the first and second internodes than in the third and fourth internodes of rhizome，suggesting that LrSSS might play an important role in starch synthase processes.

Key words: lotus rhizome, starch, LrSSS, clone, expression