Flow-induced vibration of a "xed}"xed elastic cylinder with a large aspect ratio (+58) is considered. The structural vibration is modelled by the Euler}Bernoulli beam theory, and the normal mode method is used to analyze the structural response. The #ow "eld are resolved using a "nite element method and the #ow-induced forces are thereby calculated. Altogether two di!erent cases are examined, one at resonance and another at o!-resonance. Results thus obtained are compared with experimental measurements and a discrete-parameter model [a two-degree-of-freedom (2-d.o.f.) model] analysis. The comparison shows that, while the 2-d.o.f. model gives reasonable prediction of the mid-span vibration displacements for the resonant and o!-resonant case, the present method yields the span-wise multi-mode response of the cylinder similar to that observed experimentally. Based on these results, a correction formula is derived to estimate the span-wise vibration from the 2-d.o.f. model result. Correlation results are also presented to show that #uid}structure interactions mainly a!ect the phase relation between the #uid forces and the corresponding vibration of the cylinder. Such in#uences have di!erent e!ects along the cylinder span.