UV exposure of a fluorescent polymer, diphenylamino-s-triazine bridged p-phenylene vinylene polymer (DTOPV), resulted in fluorescence quenching and a change in surface wettability via photo-oxidation. Patterned polymer films were prepared simply by exposing the polymer film to UV source through a photomask under air. The UV-exposed region was highly biocompatible and provided selective mesenchymal stem cells (MSCs) attachment on it. This allowed cell alignment and patterning along the line patterns of linear, curved, and even various letter shapes. The proliferation rate of MSCs cultured on UV exposed surface (DTOPV+UV) was higher than that of the unexposed surface, and the cells were increased to 10-fold after 6 days. The attachment of MSCs was highly selective to the UV-exposed pattern in the presence of collagen and gelatin, which induced cell patterning and attachment through hydrophilic interaction with the UV exposed area. Taking advantage of the emission from the DTOPV pattern, the cell location and pattern images were easily detected through a microscope with or without an excitation probe beam. These studies provide an exciting opportunity for novel cell patterning by a simple photopatterning process using a highly fluorescent DTOPV.