Abstract: Maturity stage is subcritical period of water demand for flue-cured tobacco. This study was to demonstrate effect of different soil moisture regimes at the maturity stage on enzyme activities of carbon and nitrogen metabolism in flue-cured tobacco in field. The results showed that: soil water deficit (50%-60% maximum field capacity) would decrease the chlorophyll content of tobacco leaves; chlorophyll content of tobacco leaves was higher when soil moisture was adequate (80%-85% maximum field capacity), however, tobacco leaves slowly matured; re-watering faded away premature of tobacco leaves by drought stress. Activities of nitrate reductase, invertase and amylase were higher in moister soil than in droughty soil; nonetheless, amylase would increase when re-watering, to some degree.