In order to elucidate the qualitative disposition and the quantitative distribution of the aromatic constituents in roughage, the volatile constituents of the green forage and hay of bahiagrass were analyzed by a combined gas chromatograph-mass spectrometer (GC-MS) and a FID-gas chromatograph (FID-GC). The area percentage of each compound in the volatile constituents and the parts per billion (ppb) concentration of each compound in the materials were calculated on a data processor for FID-GC using n-pentadecane as the internal standard. As a result, 25 compounds were identified from the volatile constituents of the green forage of bahiagrass; their area percentages and ppm values totaled 78.2 and 22.0, respectively. The volatile constituents of this green forage were quantitatively rich in alcohols, esters, and ketones. On the other hand, 26 compounds were identified from the volatile constituents of the hay of bahiagrass; their area percentages and ppm values totaled 79.4 and 12.0, respectively. The volatile constituents of this hay were also rich in alcohols, esters, and ketones. Both volatile constituents were qualitatively about the same, but were somewhat different quantitatively.