A new carboxylic acid-terminated dendronized polymer (denpol), constructed with linear chain attaching Frechet-type dendrons at each repeat unit, has been designed and synthesized through a combination of macromonomer route and hydrolysis reaction. The resulting denpol exhibits excellent solubility in aqueous solution for pH >= 6, and significantly the denpol also encapsulates various aromatic molecules efficiently. The results of UV-vis and fluorescence spectra indicate that hydrophobic and pi-pi interactions bring into effect between the water-insoluble organic molecules and the denpol. Moreover, the photoisomerization of azobenzene solubilized in denpol aqueous solution was investigated, which indicated that trans-to-cis and cis-to-trans conversions were first-order reactions. The enhancement of photoisomerization property may attribute to the proper microenvironment in the denpol. Therefore, the denpol is expected to be a potential candidate as amphiphilic unimolecular container. (C) 2008 Wiley Periodicals, Inc.