Abstract: The response of a microalgae(Chlorella sp.)strain which isolation and purification from Arctic glacial meltwater to the enhancement of UV-B radiation was explored in this study. The effects of three different UV-B radiation, i. e., 22 μW/cm~2, 45 μW/cm~2, 70 μW/cm~2 were tested on the algal growth, biochemical components, and cell ultrastructure. The results showed that UV-B irradiation could inhibit the relative growth and reduce content of pigment;and the in-hibiting effects were more significant according to the intensity increasing. Meanwhile, the SOD activity and MDA contents of the strain increased with higher UV-B irradiation. The results showed that the enhancement of UV irradiation could deepen the damage of Chlorella species and algae could adapt the higher intensity of UV-B radiation to some extent.