Water soluble conjugated polymers (conjugated polyelectrolytes) are receiving considerable interest duo to their unique properties and potential technological applications. However, as an active member of the conjugated polymer family, there are very few reported examples of water soluble PDAs. One of the reasons is the difficulty of PDA synthesis. Topochemical 1,4-polymerization of diacetylene functionalities is the well known approach to make PDAs. We have developed a novel host-guest strategy to orient the diacetylene molecules according to the topochemical requirement of 1,4-polymerization, and successfully carried out thermo polymerization of deca-4,6-diynedioic acid. The resulting polymer is soluble in aqueous base and shows interesting photophysical properties.