One of the alkaloidal components of Nelumbo nucifera embryo was isolated in crystalline form and identified with l-(p-hydroxybenzyl)-6,7-dihydroxy-l,2,3,4-tetrahydro isoquinoline. This is the first tetrahydroisoquinoline alkaloid with a secondary base isolated from Nelumbo nucifera. © 1970, The Pharmaceutical Society of Japan. All rights reserved.