On a mid-altitudinal site in southern Kyushu, land and temperature conditions are not so suitable for herbage production compared with the costal area. Normal variety, Merkeron of napiergrass (Pennisetum purpureum Schumach) was transplanted on a hilled native pasture under three planting densities to examine the suitability of the genotype in two years after establishment. Merkeron napiergrass can maintain high wintering ability, even transplanted in hilled pastures on a mid-altitudianl site. Yielding ability of the grass increased with the increase in planting density to maintain 7 Mg DM/ha for two years with higher herbage quality in digestibility than natural weeds, suggesting for the sitablity of this genotype to the regions.