[目的]了解南安市基本控制地氟病后改水工程运转情况及改水降氟的防治效果,为制定防治措施提供参考。[方法]调查6个病村的改水降氟工程运转情况、井水氟含量及8～12岁儿童氟斑牙患病率。氟斑牙按Dean分度法诊断,尿氟及水氟电极法测其含量。[结果]6个病村改水降氟工程只有1个现正常运转,其它均年久失修报废重新建井使用。6个病村水源及用户水样23份,水氟含量范围0.10～1.40 mg/L,均值0.31 mg/L,合格率为95.7%,个别水样水氟含量仍高达1.40 mg/L;调查8～12岁在校学生46人,氟斑牙患病率28.3%,低于改水前53.4%(393/736),以极轻度和轻度为主;尿氟0.33～14.96 mg/L,中位数1.13 mg/L。[结论]采用改水降氟工程可达到预期效果,须加强改水工程的维护管理和监测,防止水氟超标。 [Objective] To understand the operation of water diversion project after the basic control of ground-based fluorosis in Nanan City and the control effect of water diversion and fluoride reduction, so as to provide reference for the formulation of control measures. [Method] Investigate the operation condition of water and fluoride removal project in 6 villages, the well water fluorine content and the prevalence of dental fluorosis in 8 ~ 12 years old children. Dental fluoroscopy by Dean indexing diagnosis, urine fluorine and water fluoride electrode method to measure its content. [Results] Only one of the 6 villages to change water and fluoride was in normal operation, and others were all dismantled and scrapped to rebuild their wells. There were 23 water samples and 6 water samples in 6 villages. The fluoride content in water ranged from 0.10 to 1.40 mg / L with a mean of 0.31 mg / L and the pass rate was 95.7%. The fluorine content in individual water samples was still as high as 1.40 mg / L. The prevalence of dental fluorosis was 28.3% in 12-year-old school students, which was lower than 53.4% ​​(393/736) before water change, with mild and mild prednisone. Urinary fluoride 0.33-14.96 mg / L, Median 1.13 mg / L. [Conclusion] The water-reducing and fluoride-reducing project can achieve the expected result, and the maintenance, management and monitoring of the water diversion project should be strengthened to prevent water fluoride exceeding the standard.