【Objective】So far little has been reported in the literature about morphological transformation of heavy metal elements in coal ash applied as soil amendment and hazards of long-term application of the coal ash to the soil environment and human health, though a quite number of researchers reported that application of coal ash in agriculture is of positive significance. However, statistics of the literatures both at home and abroad indicates that most of their conclusions were based on cultivation of only one crop and analysis of yield and quality of the crop. Therefore, this paper aimed to explore transformation, migration and concentration trend of Pb, Cr and Cu in the soil-Chinese cabbage system under long-term continuous cultivation, in an attempt to provide a certain theoretical basis and support with data for use of coal ash as amendment in agriculture and ecological environment. 【Method】Chinese cabbage was cultivated for four consecutive seasons in pots of brown soil amended with coal ashes different in particle size, i.e. fine coal ash collected with a bag-type dust remover and coarse coal ash collected from a boiler furnace and different in rate, separately. In this project, samples of the soils mixed with coal ash were collected for analyses of chemical fractions of heavy metals (Cr, Cu and Pb) by following the three-step sequential extraction procedure laid down by the EC Reference Bureau (BCR). Contents of heavy metals (Cr, Cu and Pb) in the roots and edible parts of the cabbage were also determined for calculation of enrichment coefficients and transfer coefficients of the heavy metals in the Chinese cabbage and for analysis of migration behavior and bioavailability of the heavy metals in the Chinese cabbage. 【Result】Contents of HOAc(acetic acid) soluble fractions of Pb and Cr in different coal ash treatments were measured, displaying an order of 150 g·kg^-1 coarse coal ash > 150 g·kg^-1 fine coal ash > 50 g·kg^-1 coarse coal ash > 50 g·kg^-1 fine coal ash > CK, which indicates that both application rate and particle size of coal ash affected the fraction of HOAc soluble Pb or Cr in content. Analysis of distributions of Pb, Cr and Cu relative to form in the soil exhibits an order of residual fraction > reducible fraction/oxidable fraction > HOAc soluble fraction. All the findings demonstrate that Pb, Cr and Cu remains mainly as residue in the treated soils, and their contents decrease with the cultivation going on season by season. The fraction of extractable Pb and Cr accounted for 150 g·kg^-1 or more, and that of HOAc soluble ones increased with the cultivation going on season by season. However, both the fractions of extractable Pb and Cr accounted for 55% or more, and the fraction of HOAc soluble ones decreased with the cultivation going on season by season. Heavy metal enrichment ability of the plant varied in the order of Cu > Cr > Pb, all of which were lower than the threshold value of 1. Therefore, compared with Pb and Cr, Cu was higher in bioavailability. The contents of heavy metals in the root of Chinese cabbage were lower than their respective ones in the edible part, and their transfer coefficients were all > 1. Their transfer capacity was in the order of Cr > Cu > Pb, so the migration ability of Cr in Chinese cabbage was higher than the other two. 【Conclusion】With the plant growing on, contents of the heavy metal residues in the treated soils decrease gradually, while contents of the HOAc soluble fractions increase gradually, indicating that the residues become HOAc soluble. The organic acids secreted from roots of the Chinese cabbage activate the coal ash applied to soil, thus making the heavy metals in the soil gradually transform from residual form into potentially available form and/or HOAc soluble form, thereby enhancing bioavailability of the heavy metals gradually. Although the heavy metal enrichment coefficients of the Chinese cabbage are low, the heavy metal transfer coefficients are high, which will pose a safety hazard with the edible part of the Chinese cabbage.