Abstract: In order to know the relation between different varieties, different growth stages, different leaf positions and photosynthetic physiological Indexes. Through collecting and analyzing the data of photosynthetic and transpiration and chorophyl content in millet, the paper had study and sum up the photosynthetic physiological characteristics of millet. The results showed that: the net photosynthetic rate at booting stage was 247.7% and 32% higher respectively than the net photosynthetic rate at jointing stage and mid grain-filling stage, the transpiration rate at booting stage was 100.4% and 104.7% higher respectively than the net photosynthetic rate at jointing stage and mid grain-filling stage; intercellular CO2 concentration was lower jointing stage and mid grain-filling stage. The stomatal conductance was relatively higher than jointing stage and mid grain-filling stage; the top-three leaves' transpiration rate, stomatal conductance, intercellular CO2 concentration were significantly higher than the lower leaf. Chlorophyll content presented the trend from low in last glaciation to high in the middle and late holocene.