| In this paper, the lysimeter experiment was employed to study the temporal and spatial dynamics of soil moisture of flue-cured tobacco by using a tobacco(Nicotiana tobacum L) cultivar Zhongyan 100 in Nanjing city of Jiangsu Province in 2004 ～ 2005. The effects of different irrigation schedules on characteristics of water consumption, dynamics of leaf area index and leaf number, physiological index, dry matter accumulation and distribution, N, P and K contents, yield, quality and water use efficiency were also investigated. The main results were as follows:1. In the growing period of tobacco plant, changes of soil water contents within 0 to 20 cm depth layers was the most significant, followed by layers within 20 to 40cm depth and it was the most stable within 40 to 60cm depth. In addition, mathematical models describing the changes of soil water contents with time within 0 to 20 cm, 20 to 40 cm, 40 to 60 cm depth were also proposed, with which the temporal dynamics of soil water in flue-cured tobacco could be predicted. Also, it was good that irrigation calculating wetness depth was 20 to 30 cm at the root extending stage, 50 to 60 cm at the vigorous growing stage and 30 to 40 cm at the maturing stage; and the optimum relative soil water combining was better than others when it was at 60%-80%-70% or 60%-80%-60%.2. There was significant relationship between soil moisture of 0～40 cm soil layer and the mean water content of 0～60 cm soil depth, which could be expressed by the equation of y=3.6581+0.8732x0-40 in the whole growing period and y=5.5433+0.7810x0-40 at the vigorous growing stage. These equations could be used to estimate the mean water content of 0～60 cm soil depth by the moisture of 0～...
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