Five new stilbenoids, three bibenzyls, one dibenzyldihydrophenanthrene and one benzoyldihydrophenanthrene, were isolated from tubers of Bletilla striata. The new structures were elucidated as 3,3'-dihydroxy-44p-hydroxybenzyl)-5-methoxybibenzyl, 3,3'-dihydroxy-2-(p-hydroxybenzyl)-5-methoxybibenzyl, 3',5-dihydroxy-2-(p-hydroxybenzyl)-3-methoxybibenzyl, 2,7-dihydroxy-1,3-bi(p-hydroxybenzyl)-4-methoxy-9,10-dihydrophenanthrene and 2,7-dihydroxy-1-(p-hydroxybenzoyl)-4-methoxy-9,10-dihydrophenanthrene, by their spectroscopic data.