Objectives:Zhengzhou,Kaifeng and Xinxiang,the cities in the north central re-gion of Henan Province,suffered from many times floods from 2004 to 2009.We focused on dysentery disease consequences of floods and examined the association between floods and the morbidity of dysentery,based on a longitudinal data.Methods:A generalized additive mixed model was conducted to examine the relationship be-tween the monthly morbidity of dysentery and floods from 2004 to 2009 in the study areas.The relative risks(RRs)of the floods risk on the morbidity of dysentery were estimated in each city and the whole region.Results:The RRs on dysentery were 11.47(95%CI:8.67-15.33),1.35(95%CI:1.23-3.90)and 2.75(95%CI
　　:1.36-4.85)in Kaifeng,Xinxiang and Zhengzhou,respectively.The RR on dysen-tery in the whole region was 1.66(95%CI:1.52-1.82).