Abstract: A phenomenological modeling approach for establishing warm-compaction equation and curves through modifying regression equation of room-compaction curve is presented. An enhanced factor of compaction pressure is introduced into the equation to reveal effects of powder/die temperature, filling height of powder on green density.Compaction curve resulting from this equation is consistent with experimental data of ATOMET grade iron powders. The curves show that the powder/die temperature should reduce as filling heights of powders increase and that in some cases warm compaction can not give rise to high green density.