Abstract: Under phosphorus-deficiency stress, changes of abscisic acid (ABA)contents in seedling of three asparagus bean Vigna unquiculata W. ssp. sesquipedalis (L.) Verd cultivars differing in tolerance to phosphorus-deficiency were studied. The results showed that ABA contents in root increased under P-deficiency stress, ABA contents declined early, then increased to a peak, and declined again, the peak appeared earlier in cv. Erlubai (Low P-deficiency-tolerance) than cv. Luhuabai (High P-deficiency-tolerance). The increase in cv. Xianggangqingcv. Erlubaicv. Luhuabai. The ABA contents in older leaf, stem and youngest fully-expanded leaf increased under P-deficiency stress, the increase in cv. Xianggangqingcv. Erlubaicv. Luhuabai, but that in cv. Erlubaicv. Xianggangqing cv. Luhuabai at later stage. The ABA contents in younger leaf and stem increased under P-deficiency stress, the increase in cv. Luhuabai cv. Erlubai cv. Xianggangqing. The increase of ABA contents in leaf and stem under P-deficiency stress might enhance transportation of phosphorus and water, reduce membrane lipid peroxidation.