Pot experiments were performed with a barren soil amended with fly ash stabilized municipal sewage sludge to cultivate Brassica chinensis. Accumulation and transformation of heavy metals in the tested soil-plant system were investigated. The results showed that appropriate application of fly ash-sludge mixture could improve the growth of Brassica chinensis. The plants cultivated in F30 treatment, which contained 14% (volumetric) sludge and 6% (volumetric) fly ash, presented the highest yield and nutrients and better physiological characteristics. The average bioconcentration factors (BCFs) of the studied heavy metals in the Brassica chinensis cultivated in F30 treatment decreased in the order of Sb (8.05) > As (1.50) > Zn (0.84) > Cu (0.44) > Mn (0.16) > Ni = Cr (0.10) > Pb (0.07) > Co (0.06) > Cd = Ti (0.05) > Fe = V (0.02). The concentrations of Cd, As, Ni, Pb, Cr, Cu and Zn in the cultivated Brassica chinensis were lower than the maximum permissible concentrations for the vegetables in China. Planting Brassica chinensis could reduce the availability of Cu, Zn, Ni, Cr, Mn, Co, As and Sb in the fly ash-sludge amended soil. The long-term effect of repeat application of the fly ash-sludge mixture on soil and plants require further field investigation.