Abstract: Microalgae can receive cold stimuli from cellular in the same way as higher plants.Low temperature can be considered as the external environmental signal, and the cells can transfer cellular stimuli through the processes of transmission, cascade and / or change the compositions of themselves' structure and / or secrete metabolites against low temperature environment. In this article Ca2 +signaling pathways, active oxygen species ( ROS) and cells' responses to low temperature were mainly reviewed including antioxidant defense, MAPKs pathways and metabolites accumulation of microalgae, in order to provide some ideas and ways for scale- up production metabolites from microalgae.