Phenylazomethine dendrimers, which can be used as the template for precise metal nanoparticles, are soluble only in aprotic media. The use of a specific surfactant enabled their solubilization in aqueous solutions. Under dilute condition, they formed discrete micelles with a size close to the that of the dendrimer. Condensation resulted in their aggregation; however, they remained in a homogeneous solution without precipitation. Furthermore, each micelle was well isolated. The triplet-excited state of the zinc porphyrin core in the micelles was significantly stable, suggesting the formation of rigid core-shell micelles preventing any external molecules from approaching to the core.