生物量（Biomass）是指一条食物链可支持的生物总质量，一个动物或植物物种的活个体的总量或重量，称为物种生物量，而群落中所有物种活个体的总量或重量，称为群落生物量。

生物量通常以生境的单位面积或单位体积来表示，常以每单位的干质量计算。

Biomass, in ecology, is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms, plants or animals. The mass can be expressed as the average mass per unit area, or as the total mass in the community.