Abstract: Bacillariophyta and Chlorophyta are main dominant phytoplanktons in winter and spring in Meiliang Bay, located in the north of Lake Taihu. Changes of algal growth and phytoplankton community were studied in an experiment within different water temperatures and nutrient conditions, which was conducted in Taihu Laboratory for Lake Ecosystem Research (TLLER) in January 2013.Non-enhancive temperature was set as control, and five water-temperature gradients (i.e., non-enhancive temperature, 12.0,4.0,6.0,8.0and 20.0℃) and three nutrient gradients (i.e., low, middle and high) were designed in the experiment. The results showed that total Chla concentration of lake water increased as the water temperature increased and was significantly higher under temperature of 20.0℃(0.19-12.94μg/L) than other water temperature treatments (0.01-6.83μg/L). Meanwhile, concentrations of nitrogen and phosphorus significantly declined under higher water temperature(16.0,8.0and 20.0℃)compared with lower water temperature (non-enhancive temperature, 12.0and 14.0℃). Furthermore, total Chla concentration increased when nutrient was added in the lake water. Chlorophyta was dominant phytoplankton species at the beginning of the experiment. However, Bacillariophyta rather than Chlorophyta became main algae especially under the middle and high nutrient conditions with the proportion of Chla concentration from 50% to 75%-98%. The study revealed that Bacillariophyta had an advantage in the competition with Chlorophyta in nutrient-added treatments with daily average value of Chla concentrations from 0.52-4.07μg/L and 0.17-0.52μg/L respectively. It suggests that enhanced water temperature limited the growth of Chlorophyta added nutrient treatments, and the Chla concentration of Chlorophyta was influenced by nutrient concentration as well. Therefore, the effect of water temperature on phytoplankton community are as important as that of nutrient concentration in winter and spring season in Lake Taihu and more researches should be further taken in the future.