Abstract: The photosynthetic characteristics of Photinia serrulata and Photinia frasery Dress were measured in the field conditions using CIRAS-2 portable photosynthetic system made by the company of UK PP Systems. The result showed that both Photinia serrulata and Photinia frasery Dress had a double-peak curve of diurnal variation of photosynthesis and a phenoenon of photosynthetic“noon breaking” in sunny days. Light saturation points of Photinia serrulata and Photinia frasery Dress were 1 200-1 400 μmol·m^-2·s^-1 and 1 400-1 600 μmol·m^-2·s^-1 respectively，light compensation points of them were 127.00 μmol·m^-2·s^-1 and 59.26 μmol·m^-2·s^-1 respectively，and photosunthetic apparent quantum yield of them were 0.02000 and 0.02216 respectively. The experimental results showed that Photinia serrulata and Photinia frasery Dress belongs to light species，and the shade tolerance and light adaptability of Photinia frasery Dress was better.

Key words: Photinia serrulata, Photinia frasery Dress, photosynthetic characteristics