A lectin (HTTL) was isolated from Helianthus tuberosus L. (wild sunflower) tubers using ion-exchange chromatography, gel filtration, and affinity chromatography. The lectin agglutinated both untreated  and trypsin-treated rabbit erythrocytes and did not agglutinate human blood cells of groups A, B, and O. The gel filtration showed the native molecular mass of 72kDa and subunit molecular masses of 17 and 18.5k Daon 12% SDS–PAGE. The lectin activity was inhibited by D D-mannose.The tetrameric protein revealed a unique characteristic by formin gabroadzone of protein innative PAGE at pH 8.3, which dissociated into seven sub units of varying e/m ratios on acid gel at pH4.3. These seven bands revealed two poly peptides pecies of molecular masses 17 and 18.5k Da on 12% SDS-PAGE, as in the case of the native protein. There sult indicated that of these ven sub units, three were homotetramers of 17kDa, one was a homotetramer of 18.5k Da, and three were heterotetramers of 17 and 18.5k Da. The lectin was thermo stable with broad pH optima (pH 4–8) and had no requirement for divalent metal cations for its activity. The amino acid composition showed that the lect in contained higher amounts of glycine, alanine, and lysine, but no methionine. The sugar content was estimated to be 5.3% mannose equivalent. The HTTL was mitogenicto mouse spleen (total) cells at 25μg/ ml concentration. The lectin showed characteristics different from those of the earlier reported H. tuberosus tuber lectinsandhence open supane wavenue to investigate the structure–function relationship of lectin in Helianthus species.