初级生产（英语：primary production），又称初级生产量，是指从大气中或水中的二氧化碳合成有机化合物。它主要是通过光合作用的过程，利用光作为能量来源；但它也是通过化能合成，其使用化学化合物的氧化或还原作为能量来源。这是生态系统中最基本的能量固定，所以具有奠基石的作用，所有消费者和分解者都直接或间接地依赖初级生产为生，因此没有初级生产量就不会有消费者和分解者，也不会有生态系统。负责初级生产的生物被称为初级产品生产者或自养生物，并构成了食物链的基础。在陆地生态区域，这些主要是植物；而在水生生态区，藻类负有主要责任。

In ecology, primary production is the synthesis of organic compounds from atmospheric or aqueous carbon dioxide. It principally occurs through the process of photosynthesis, which uses light as its source of energy, but it also occurs through chemosynthesis, which uses the oxidation or reduction of inorganic chemical compounds as its source of energy. Almost all life on Earth relies directly or indirectly on primary production. The organisms responsible for primary production are known as primary producers or autotrophs, and form the base of the food chain. In terrestrial ecoregions, these are mainly plants, while in aquatic ecoregions algae predominate in this role. Ecologists distinguish primary production as either net or gross, the former accounting for losses to processes such as cellular respiration, the latter not.