A new regioisomer of andrographolide, 17-hydro-9-dehydro-andrographolide (1), and five new sulfates of andrographolide (2-6) were isolated from Xiyanping, a China licensed anti-inflammatory drug derived from andrographolide through sulfation reaction. Their chemical structures were elucidated by spectroscopic and chemical methods. The inhibition effects of these compounds on angiogenesis were evaluated by rat aortic ring assay. Compounds 1 and 3 exhibited strong inhibitory activities on vascular endothelial cell tube formation in rat aorta ring at the concentration of 1 μM. Compounds 4 and 5 showed moderate suppression on angiogenesis at 10 μM.