Re- selection w as made in adv anced generation of soy bean st rain Su89- 2. The useo f method of approximate calculatio n o f multiple no rmal di st ribution in soy bean purelineselectio n w as fi rstly int roduced in the paper. Th e number of plants ( basic po pulationsi ze) needed in multiple character selectio n fo r di fferent dema nds w ere estimated bythe new method.