Abrus pvecatorius agglutinin (APA) has been purified by a new purification procedure from the seeds of semen jequiriti produced in Bangladesh and Taiwan. The method was accomplished by 33-50% saturation ammonium sulfate fraction from 1% acetic acid extract of the seeds of semen jequiriti using gel filtration on Sephadex G-75 followed by DEAE-cellulose column chromatography. The molecular weight was estimated to be 126,000 and 122,000 by gel filtration on Sephadex G-150 for Bangladesh-APA and Taiwan-APA, respectively. Both the APA were found to be consist of two types of polypeptide chains of nearly same size (30,000 to 34,000), which possess valine and proline as N-terminal amino acid. Furthermore, one of the constituent polypeptide chains of APA showed microheterogeneity, suggesting that APA is a mixture of isolectins.