From April 2016 to February 2017, the temporal-spatial distribution of phytoplankton primary production in Lake Chenghai at Yunnan, China was investigated monthly via light-dark bottle method (at a dock site) and vertically generalized production model (VGPM) (across nine sampling sites), and the potential influencing factors were also analyzed. The results showed that the annual mean values (mean±SE) of gross primary production (GPP_C), net primary production (NPP_C) and respiration (R_C) of water column (0-3 m) at dock site were 5.40×10³±0.64×10³, 2.36×10³±0.63×10³ and 3.06×10³±0.82×10³ mg O₂/(m²·d), respectively. Meanwhile, the maximal and minimal values of the GPP and NPP per biomass (GPP/Chl.a and NPP/Chl.a) in vertical profile were both present at the depth of 0.5 m and 3.0 m respectively, whether during spring and summer (from April to August, 2016), autumn and winter (from September 2016 to February 2017) or the entire experimental period at dock site. Moreover, the annual mean value and range of the phytoplankton primary production (PP_eu) estimated by VGPM were 6.54×10³±0.30×10³ and 2.74×10³-18.62×10³ mg C/(m²·d), respectively. PP_eu increased rapidly during spring and summer, and fluctuated during autumn and winter. No significant difference for PP_eu was detected between spring-summer and autumn-winter. The spatial heterogeneity of PP_eu was weak in general despite the significant difference in the north-south direction in July and August with plentiful rainfall which might be related to the rainfall and spatial heterogeneity of nutrients input from the basin. Furthermore, although the major influencing factors for PP_eu and their relative importance were changed with season, the phytoplankton biomass was the most important factor impacting PP_eu during the entire period, and the water temperature was also an important factor during spring and summer.