Water soluble poly[2‐(diisopropylamino)ethyl methacrylate]‐block‐poly[2‐(dimethylamino) ethyl methacrylate]‐block‐poly[2‐(N‐morpholino)ethyl methacrylate] triblock copolymers are synthesized via group transfer polymerization. They are molecularly soluble in acidic solution but give PDPA‐core three‐layer “onion‐like” micelles in alkaline solution. They also give two types of micelles in hexane depending on whether a cosolvent is used: i) PMEMA‐core “onion‐like” reverse micelles are formed with a cosolvent, or, ii) [PDMA‐b‐PMEMA]‐core core–shell micelles without. In addition, novel shell cross‐linked micelles and reverse SCL micelles are also synthesized by cross‐linking the inner PDMA shell of both PDPA‐core micelles in water and PMEMA‐core reverse micelles in hexane.