A new kind of water-soluble asymmetric hyperbranched poly(amide-ester)s was synthesized by direct polycondensation of benzene-1

2

4-tricarbonylic acid-1

2-anhydride (BTAA) and diethanolamine (DEA) via pseudo-divergent or one-step approach．The terminal groups of the hyperbranched polymer can be controlled by the feed molar ratio of BTAA to DEA. The resulting hyperbanched poly(amide-ester) was characterized by FTIR spectra

1H-NMR spectra

and TGA．No gelation was observed when the feed molar ratio of BTAA to DEA was higher than 2.04 in one step approach

while gelation did occur when the ratio was lower than 2．In pseudo-divergent approach

it was not necessary to separate the obtained oligomers or macromolecules in each step

and hyperbranched polymers with high molecular weight were prepared．Compared with the divergent approach utilized in the synthesis of dendrimers

the pseudo-divergent approach is much simpler and more convenient

which might be useful in the large-scale fabrication of highly branched polymers．