Diurnal changes of the photosynthetic characteristics of Camellia crapnelliana and Camellia oleifera and the environmental factors were determined using Li-6400 portable photosynthetic system. The results showed that C. crapnelliana had a bimodal curve of the diurnal change in the net photosynthetic rate with a peak of 20.2 μmol·m^-2·s^-1 and a highly efficient photosynthesis occurred during 9:10 and 13:10（19.7-20.2 μmol·m^-2·s^-1). The diurnal changes of the stomatal conductance in C. crapnelliana were similar to C. oleifera, showing a “single peak curve” modal without a significant midday depression phenomenon with a peak of 0.22 mmol·m^-2·s^-1 at 13:10. The transpiration rate of C. crapnelliana was generally higher than that of C. oleifera. C. oleifera showed no an obvious photosynthetic depression and the maximal net photosynthetic rate was 20.1 μmol·m^-2·s^-1 at 11:10. The results suggested that C. crapnelliana may have a longer daily photosynthesis time and a higher photosynthetic efficiency than C. oleifera.