The contrasting chemical structures of the aromatic backbone and the aliphatic side chain of PII-2T (Figure ) offers a possibility to dissolve the polymer into various solvents that exhibit either selective solubility to one or mutual solubility for both the backbone and the side chain. The solvent selectivity has been shown to have significant impact on the solutionstate structure and assembly of conjugated polymers . In this work, we choose seven common organic solvents shown in Figure to tune the solution-state structure and classify them into three categories based on their selective nature: (i) a backbone solvent 1chloronaphthalene (CN) with an aromatic naphthalene ring substituted with a halogen atom, (ii) a side chain solvent decane with a saturated aliphatic structure, and (iii) solvents mutually dissolving backbone and side chain with a benzene ring with varied substituents, including 1,2,4-trichlorobenzene (TCB), 1,2-dichlorobenzene (DCB), chlorobenzene (CB), tetralin and toluene. To reveal the nature of polymer-solvent interaction in those organic solvents for PII-2T, optical and electron microscopy, UV-vis absorption spectroscopy, SAXS measurements are conducted on PII-2T solution at a concentration of 10 mg ml -1 relevant to solution processing.