Abstract: Insulation riser made of the cenospheres has good insulation effect by using in casting production. The time of solidification of steel liquid in the riser are delayed, Not only the shrink hole, shrink porosity are eliminated but also the feeding efficiency of riser is increased obviously. Raise efficiency and yield of casting technology have increased by (10-20)% and (10-13)% respectively. Metal liquid, source of energy are saved.