Objective To investigate the hemorrhagic risk factors of cerebral arteriovenous malformations (AVM) on angioarchitecture. Methods 201 cases with AVM diagnosed by digtial subtraction angiography (DSA), including 60 cases by superselective DSA, were devided into two groups. The bleeding group consisted of 138 (68.66%) cases, with ages ranging from 7 to 60 years (average 26 years). The nonbleeding group had 63 (31.34%) cases, whose ages ranged from 11 to 68 years (average 37 years). 14 risk factors with 45 levels were studied by SAS Statistical package. Results The proportion of the total value of square of mean diameters was in partial distribution between the supplying arteries and drainage veins (∑D 2 A/∑D 2 v) in the two groups. Rank sum tests showed significant difference ( P