Luminescent bacteria are those ubiquitously distributed microorganisms that emit visible light due to their naturally existed light-production genes: lux. A bioluminescent test, which offers benefits of rapidity, sensitivity and reproducibility for routine toxicity monitoring, gained growing attention these years, and it is usually chosen as an effective tool for early warning system based on its quick response and low cost. Genetic manipulation involvement equips the bioluminescent assays using several specific responsive strains with the ability of toxicity classification. This paper reviews the latest progress in luminescent bacteria for environmental toxicity testing. Description of the luminescent bacteria assays including natural luminescent bacteria test, light-emitting genetically modified bacteria test, as well as the recent research of the utilization of the bioluminescent assay for determination of water quality are all reviewed in this article.