Abstract: Aquatic ecosystems contribute more than half of the atmospheric methane (CH₄), and phytoplankton is not only a major primary producer but also a potential source of CH₄. In this paper, five widespread marine phytoplankton species were selected to recognize their potential CH₄ production rates and their influencing factors by conducting phytoplankton culture experiments. We found that the Synechococcus sp. PCC7002, Prorocentrum dentatum and Nitzschia closterium could produce CH₄ under oxic conditions with production rates of 21.11, 24.30 and 5.46 ag/(cell·d). Chaetoceros curvisetus and Skeletonema costatum cannot produce CH₄. Environmental factors including temperature and light intensity significantly influenced phytoplankton CH₄ production rates. During the exponential growth phase, under constant light intensity (1 980 lux), the CH₄ production rates of Synechococcus and Nitzschia closterium exhibited a gradual decline with increasing temperature (15 °C ＞ 20 °C ＞ 25 °C). At a constant temperature of 20 °C, interspecific differences in light response were observed: the CH₄ production rate of Synechococcus followed 3 960 lux ＞ 1 980 lux ＞ 6 000 lux, whereas that of Nitzschia costerium showed 3 960 lux ＞ 6 000 lux ＞ 1 980 lux. Under the experimental conditions of 20 °C and 3 960 lux, both species achieved relatively higher CH₄ yields, with Synechococcus and Nitzschia closterium producing 28.10 and 12.99 ag/(cell·d), respectively. Within specific temperature and light ranges, lower temperatures (15-20 °C) and moderate light intensity (3 960 lux) enhanced CH₄ production in both species. In summary, this paper confirms that the tested algae possess aerobic CH₄ emission potential, with phytoplankton CH₄ production being synergistically regulated by temperature and light intensity. The observed interspecific response variability underscores the significant environmental dependency of algal-driven CH₄ emissions in aquatic ecosystems.