Abstract:The photosynthetic characteristics of current and one-year-old Larix olgensis Herry.、Larix kaempferi Carr. and Larix gmelini Rupr. needles at elevated CO2 concentration were measured with a Li-6400 portable gas analyzer. The results showed that: elevated CO2 concentration increased the maximum net photosynthetic rate （Pmax） and respiration(Rd) of the three Larix species in different degree, and the Pmax of the current and one-year-old needles of Larix olgensis Herry. increased 91% and 83% than the control needles, respectively，that of Larix kaempferi Carr. increased 71% and 94% than the control needles, respectively，and that of Larix gmelini Rupr. increased 32% and 106% than the control needles, respectively. Elevated CO2 decreased the light compensation point (LCP) of all current needles except the Larix gmelini seedlings, indicating that the current seedlings were more sensitive to the elevated CO2 concentration. Elevated CO2 concentration increased the light saturation point (LSP) of current and one-year-old Larix kaempferi seedlings, showing that the enhanced potential of photosynthetic capacity was stronger. Under the elevated CO2 concentration conditions, the maximum apparent quantum efficiency (AQYmax) of all seedlings was increased except the one-year-old Larix gmelini. We conclude that, under the elevated CO2 concentration conditions, Larix kaempferi has the greatest growth potential and the strongest ecological advantages, Larix olgensis is the second, Larix gmelini is the lastest.