EN
The results of a study of Cs_{2} fluorescence excited by different blue lines of the Ar^{+} laser are reported. Special attention was paid to the analysis of the narrow fluorescence band at 522 nm. Approximate assignments of the fluorescence transitions were obtained. The origin of the observed fluorescence is discussed and a rough reconstruction of a fragment of the E'(3)^{1}Π_{u} upper-state potential curve is presented and found to be nearly parallel to the corresponding portion of the ground-state X^{1}Σ^{+}_{g} potential curve.