To evaluate active principles for diabetic complications from the black bamboo leaves, Phyllostachys nigra, eight compounds were isolated and tested for their effects on rat lens aldose reductase and advanced glycation endproducts. As a result, luteolin 6-C-(6''-O-trans-caffeoylglucoside) was found to show a strong aldose reductase and advanced glycation endproducts inhibition. This compound showed antioxidative activity measured in Photochem apparatus. It is concluded, therefore, that luteolin 6-C-(6''-O-trans-caffeoylglucoside) (6), a flavone of this plant, have antioxidative as well as aldose reductase and advanced glycation endproducts inhibitory effects. As a result, this compound could be offered as a leading compound for further study as a new natural products drug for diabetic complications.