Abstract: Photosynthetic characteristics of three sweet cherry cultivars Sato Nishiki, Stella and Napoleon Bigarreau were studied comparativelywith the CIRAS-2 photosynthetic instrument. The results showed that diurnal change in net photosynthetic rate ( Pn) of mature cherry leaves was a typical bimodal curve determinately regulated by stomatal conductance. The responsive curves of photosynthesis in mature cherry leaves to the change of photosynthetic active radiation, CO₂ concentration and air temperature can be described with
quadratic equations. The light compensation point (LCP) of different cherry cultivars was 10 - 82 μmol·m^{- 2} ·s^{- 1} , light saturation point (LSP) was 970 - 1 040 μmol·m^{- 2} · s^{- 1}. Stella had the lowest LCP among the three cultivars, while Sato Nishiki had the highest LSP. The CO₂ compensation point (CCP) was
90 - 116μmol·mol^{- 1} , and the CO₂ saturation point (CSP) was 1 030 - 1233 μmol·mol^{- 1}. The CCP of Sato Nishiki was lower but with higher CSP, and its carboxylation efficiency (CE) and maximal Pn ( Pm) preponderated over the other ones are obviously. The suitable temperature scope of sweet cherry photosynthesis changed from 11℃ to 36℃, and the most suitable temperature was between 23℃and 25℃, in which Pn of Sato Nishiki exceeded the other two cultivars significantly.

Key words: Cherry, Ecological factor, Photosynthetic characteristics, Stomatal limitation