Based on the in-situ measurement of Eucalyptus leaf photosynthesis in different growing seasons by the comprehensive observation tower of the Eucalyptus Forest Ecosystem Observation and Research Station in Guangxi, this paper constructs a seasonal variation data set of photosynthetic characteristic parameters of Eucalyptus urophylla × Eucalyptus grandis. This data set contains five characteristic parameters of photosynthesis of Eucalyptus leaves in northern Guangxi: Rubisco maximum carboxylation rate (Vcmax), maximum electron transfer rate (Jmax), dark respiration rate (Rd), photorespiration rate (Rp), Carbon dioxide compensation point (Γ). A photosynthetic instrument (Li6400) was used to measure the A-Ci curve of the canopy sun health leaves, and each sample tree was repeated 6 times. According to the saturation light intensity obtained by fitting the Photosynthesis-light response curve, the corresponding photosynthetically active radiation is set, and the CO2 concentration gradient is 50, 100, 150, 200, 300, 400, 600, 800, 1000, 1200, 1600, 2000 μmol/mol. The flow rate is 500 μmol/s, the minimum waiting time is 60 s, and the maximum waiting time is 300 s. The photosynthetic characteristic parameters are fitted using the Ethier & Livingston model. The measurement periods are January, June, July, September and November in 2019. 6 replicates are made for each measurement. The leaf photosynthetic characteristics dataset of Eucalyptus plantation in Guangxi can provide data support for the comparative study of different plant species and the parameter optimization of the gas exchange model of Eucalyptus forest.