Abstract: In order to screen new varieties of Amaranthus hypochondriacus suitable for cultivation in northeast China with high yield, 10 new strains of Amaranthus hypochondriacus strains（LX006,LX010,LX011,LX012,LX013,LX014,LX018,LX019,LX021,LX022）were selected as the research materials, and the photosynthetic indexes（net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO₂ concentration and chlorophyll content） of their leaves were measured and analyzed. The results showed that the daily changes of net photosynthetic rate, transpiration rate and stomatal conductance of the 10 new Amaranthus hypochondriacus varieties all showed a "double peak" type, and the first peak value appeared at 10:00 AM,and the second peak value appeared at 14:00 PM. The photosynthetic rate, transpiration rate and stomatal conductance peak values of LX014 strains of Amaranthus hypochondriacus were the highest, which were 26.12 μmol/（m~2·s）,6.78 mmol/（m~2·s）and 0.258 μmol/（m~2·s）,respectively. LX014 new strain also had the highest chlorophyll content, which was 1 203 mg/m~2,followed by LX012 new strain of Amaranthus hypochondriacus. The intercellular CO₂ concentration of 10 new Amaranthus hypochondriacus varieties all showed a "W" type. LX006 had the lowest net photosynthetic rate, transpiration rate, stomatal conductance and chlorophyll content. The results indicated that the new strains of LX014 and LX012 had obvious advantages in photosynthetic characteristics and they had the potential to cultivate new Amaranthus hypochondriacus varieties with high yield.