Abstract: Microglia, as the resident macrophage in the central nervous system, play an important role in the surveillance of microenvironment and active defense, which plays a pivotal role in the pathogenesis of age-related macular degeneration (AMD). Amyloid β (Aβ) is an important component of drusen in patients with AMD, and microglia accumulate obviously around drusen. Aβ could induce the activation of microglia, however, over-activated microglia result in the damage of retinal pigment epithelium (RPE) and the apoptosis of photoreceptor, secreting many pro-inflammatory factors and exacerbating the progression of AMD. The generation and accumulation of Aβ is the main pathologies in Alzheimer's disease (AD), more activated microglia with amoeboid morphology gathering within or nearby the senile plaques were evidenced in the pathological sections of brain tissue from patients with AMD. In Parkinson's disease (PD), the damage and death of dopaminergic neurons are accompanied by an increasing number of activated microglia in the surrounding area of substantia nigra. There is also a great number of activated microglia in the brain of amyotrophic lateral sclerosis (ALS). Thus, suppression of microglia activation might provide a novel therapeutic strategy to treat the neurodegenerative diseases including AMD.(Int Rev Ophthalmol, 2020, 44：187-191)