Аннотация:The macromonomers of the dyad (OYO) and triad (OYOYO, OYTYO) structure (with О being diphenylene oxide, T being terphenylene, and Y being the phthalide cycle) as well as a series of (co)polyarylenephthalides with general formula [(OY)p(TY)q]n differing in the ratio between the diphenyleneoxyphthalide p and terphenylenephthalide q groups (p : q = 0 : 1, 1 : 1, 2 : 1, 3 : 1, 1 : 0) have been synthesized. Photooptical and emission properties of the solutions and thin films of the synthesized (co)polymers and their aggregates formed upon the addition of a bad solvent have been investigated.