Organic luminescent materials carrying no phenyl rings have attracted much interest from researchers due to their excellent biocompatibility and good biodegradability, which make them available for potential applications in a variety of biomedical areas, such as fluorescent bioprobe, drug delivery and gene carrier, and provide a new insight into the photophysical process of light emission. In this work, we studied the optical properties of poly[(maleic anhydride)-alt-(vinyl acetate)] (PMV), a pure oxygenic nonconjugated polymer and proved that the origin of its emission was associated with the clustering of the locked carbonyl groups. PMV exhibits solvatochromism: after interaction with electron-rich solvents, its absorption and emission shift to the longer wavelength region due to the formation of polymer/solvent complexes. This enables fine-tuning of its optical property by varying the solvent without the need of changing the chromophore.