The degradation of chloroplast pigments and changes of respiratory intensity, moisture content and specific leaf weight in TN90 during air-curing were studied by field experiments. The results showed that the contents of chl, chla, chlb and carotene in TN90 increased with the elevation of stalk position, decreased with the proceeding of air-curing, and chloroplast pigments in the order of decrease rate were chla>chl>chlb>carotene during air-curing. The durations of the highest decrease rate of chla in lower, middle and upper stalk positions were 0-6d, 0-9d and 0-12d, respectively. The other pigments decreased gently. The ratio of chla/chlb and chl/carotenoid decreased with the proceeding of air-curing, which was beneficial to leaf quality. Along with the moisture dissipating during air-curing, the moisture content in leaves decreased gradually, and the life activity of leaf cells was weakened also, which led to the decrease of respiratory intensity and specific leaf weight.