A study on Fischer-Tropsch synthesis (FT S) reaction over an activated carbon supported iron catalyst (Fe/AC) was conduct ed in one liter autoclave slurry bed reactor by using different reduction ways, i.e. reduction in the slurry bed reactor or in the fixed bed reactor. The pre treatment result showed that the reduction temperature for Fe/AC catalyst is hig h (>280?℃). It was found that the catalyst was able to be reduced in the slur ry bed reactor at a high pressure, and the catalyst activities increased with th e increase of reduction temperature in a certain temperature range. Comparing w ith the results of the catalyst reduced in the slurry bed reactor, the conversio ns, yields and product distribution of the catalyst reduced in the fixed bed wer e all superior, this makes the outer reduction-transfer way being more applicab le for Fe/AC catalyst in developing slurry technology. XRD analysis found that there exist two kinds of active sites, Fe XC and Fe 3O 4, on the used Fe/AC c atalyst.