Objective: To evaluate the effect of slow release microcapsules of bFGF on implanted vein graft. Methods: The vein graft stenosis model was made in 24 New Zealand rabbits. Group I (n=8) served as control group, group II (n=8) as blank microcapsule group, group III(n=8) ,each microcapsule contains 1?g bFGF as bFGF group. In group II and III,5 blank microcapsules or bFGF slow release microcapsules were implanted close to the vein graft respectively. Animals were sacrificed 5 weeks later for assessment of reendothelialization, neointimal thickening and for analysis of in vitro vasoreactivity. Results: As compared with group I and II,rabbits treated with bFGF showed remarkbale degree of reendothelialization [group I (4.08?1.61)mm 2, group II (3 93?1 54) mm 2 vs. group III (12.93?2.030 mm 2, P