Abstract: Two series of crosslinking polyurethaneurea (PUU) aqueous dispersions were prepared from polyether polyol，isophorone diisocyanate，dimethylolpropionic acid and ethylenediamine，in which castor oil and trimethylolpropane were used as internal crosslinking agents respectively. The properties of the cross-linked PUU aqueous dispersions and their films were investigated. The results showed that for these aqueous dispersions，the particle size increased as the crosslinking agent content increased，but the polydispersity index was very narrow (≤1.15). Compared with the linear PUU aqueous dispersion，the cross-linked PUU one exhibited larger particle size but the film prepared with the latter exhibited excellent waterproof performance and mechanical properties. The water absorption ratio of the cross-linked PUU films decreased from 52.4% to 12.0%.