The field experiments was conducted in the spring and winter cropping seasons 2010 at Hanoi University of Agriculture to detennine the effects of plant densities (2.86 plants/m2-M1, 3.57 plants/m2-M2, 4.76 plants/m2-M3 and 7.14 plants/m2-M4) on the SPAD value, leaf area index, dry matter accumulation, fresh yield and yield components of a short-duration taro cultivar (KS5). Tile results showed that the leaf are index (lAI) increased as plant density increased at 60, 75 and 90 days after planting (DAP) under both cropping seasons. However, SPAD value (a parameter highly positive correlated to chlorophyll content) and L/R ratio (dry weight of leaf/dry weight of conn+connel+root) were not significantly affected by plant density (p0.05). The crop growth rate was increased as plant density increased in both cropping seasons. As increasing the plant density, the number of connels/hill and conn weight were decreased, but the number of connel/m2 was increased. This was the main factor that contributed to the higher yield in the high plant density treatments. The highest yield was obtained in M4 (19.0 ton/ha and 16.7 ton/ha in the spring season and winter season, respectively).