Four generations of new amphiphilic thermoresponsive linear-dendritic block copolymers (LDBCs) with a linear poly(N-vinylcaprolactam) (PNVCL) block and a dendritic poly(benzyl ether) block are synthesized by atom transfer radical polymerization (ATRP) of N-vinylcaprolactam (NVCL) using dendritic poly(benzyl ether) chlorides as initiators. The copolymers have been characterized by H-1 NMR, FTIR, and GPC showing controlled molecular weight and narrow molecular weight distribution (PDI1.25). Their self-organization in aqueous media and thermoresponsive property are highly dependent on the generation of dendritic poly(benzyl ether) block. It is observed for the LDBCs that the self-assembled morphology changes from irregularly spherical micelles, vesicles, rod-like large compound vesicles (LCVs), to the coexistence of spherical micelles and rod-like LCVs, as the generation of the dendritic poly(benzyl ether) increases. The results of a cytotoxicity study using an MTT assay method with L929 cells show that the LDBCs are biocompatible. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 300-308