A Rh-catalyzed reaction of C-60 and C-70 with organoboron compounds is described. This new catalytic method enables introduction of various organic groups onto C-60 and C-70. [Rh-(cod) (MeCN)(2)]BF4 proved to be the most effective catalyst in terms of productivity and selectivity. The reaction generally proceeds with a high regioselectivity and in a mono-addition selective manner. It was found that water is an essential additive to promote the reaction. By X-ray crystal structure analysis, we have confirmed the reaction site of organometallic-based hydroarylation of C-70 for the first time. Various functional fullerenes, such as fullerene-tagged amino acids and fullerene-capped pi systems, can be synthesized. The X-ray crystal structure of biphenyl-attached C-60 revealed an interesting opportunity for the well-organized alignment of bucky balls by taking advantage of CH-pi interactions.