Abstract: The chlorophyll fluorescence technique applied to study on the changes of fluorescence parameters of the microalgae exposed to the environmental stresses was reviewed. Various kinds of environmental factors (light, temperature, pH, N, P, chemical substances, heavy metals) that impacted microalgae chlorophyll fluorescence parameter were summarized. By observing the changes of chlorophyll fluorescence parameters of microalgae, the changes of photosynthesis process were presented, thus reflecting the effects of environmental stress on microalgae. It may supply references to the observation of microalgae physiology, ecology and the monitoring of water quality. Microalgae play significant roles as leading primary producer in the water. It may provide alternative approach or standard for the environmental monitoring by researching microalgae chlorophyll fluorescence.