The interaction of amphipilic spin labels with beta-cyclodextrin was investigated using conventional electron spin resonance (ESR) spectroscopy to explore the aggregation of cyclodextrins in water. Methyl 5-doxylstearate (5-DMS) and stearic acid spin probes (n-DSA), which contain a cyclic nitroxide moiety with unpaired electrons covalently linked to the aliphatic chain carbon in positions 5, 7, 12, and 16, show that different dynamic domains coexist in beta-CD water solutions above 3 mM. The results are consistent with the formation of beta-CD self-assembled structures in water above a critical aggregation concentration and confirm the previous findings that were reported in the part I article of this series.