Abstract: To clarify the effect of irrigation water chlorine content and irrigation times on chlorine content in flue-cured tobacco leaves, irrigation water with low (7.7 mg/L), medium (24.6 mg/L) and high (43.2 mg/L) chlorine content were used to irrigate tobacco plant once, twice, and three times (each irrigation volume was 525 m3/hm2), 9 treatments field trials in total. The results showed that: increase in both irrigation water chlorine content and irrigation times can significantly increase the chlorine content of mature and roasted leaves.chlorine content in mature and roasted leaves of middle and upper part of tobacco. which were irrigated three times by low-chlorine water, were only 0.43%-0.49%,However, under the condition of medium-chlorine water irrigation, the mature and roasted leaves of the middle and upper part of tobacco, which were irrigated once, twice and three times, contained the lowest (0.51%-0.55%); medium (0.61%-0.72%) and highest (0.8%) chlorine content respectively; under the condition of high-chlorine water irrigation, the chlorine content in leaves of tobacco, which were also irrigated once, twice and three times were 0.59%-0.64%, more than 0.85%, and more than 1.1% respectively. The relative contribution rate of one and two more times of irrigation by medium chlorine water to the leaf chlorine content were 19.2%-30.9% and 31.3%-54.5% respectively, while, the relative contribution rate of one and two more times of irrigation by high chlorine water to the leaf chlorine content were 44.1% and 86.4% respectively. In summary, irrigation water chlorine content and irrigation times can affect the chlorine content of flue-cured tobacco leaves significantly, and the high chlorine water irrigation has the greatest impact. So, to control the chlorine content of tobacco leaves within the appropriate range of 0.3%-0.8%, tobacco plant should be irrigated by low chlorine water, medium-chlorine water irrigation should be rationally limited, and high-chlorine water irrigation should be controlled.