目的探讨洞庭湖垸外血吸虫病易感地带距大堤不同距离湖洲野粪分布特点及与感染螺密度的关系。方法１９８７～１９９４年，选择洞庭湖区３０个村外洲进行了观察。结果，野粪污染湖洲以牛、猪、人为主，离大堤愈近，密度愈高。牛粪在各距离中均占绝大多数，且离堤愈远比例愈高；猪粪集中分布在距大堤３００ｍ内；人粪呈散在分布。结论＜３００ｍ，各年感染螺密度均＞０．００５只／０．１１ｍ２，属一级易感地带，且与野粪密度有直线相关关系；然两者均呈逐年下降之势。３００ｍ外，年间虽有变化，但无规律 Objective To investigate the distribution characteristics of the stool and the density of infected snails in lake lakes at different distances from the embankment in the embankment outside the embankment of the embankment. Methods From 1987 to 1994, 30 villages in the Dongting Lake area were surveyed. As a result, the lacustrine contaminated lake was dominated by cattle, pigs and people, and the closer it was to the embankment, the higher the density. Cattle dung accounted for the vast majority of all distances, and the farther away from the embankment, the higher the proportion of pig manure distributed within 300m from the embankment; human waste was scattered. Conclusion <300m, the average density of infected snails in each year is> 0.005 /0.11m2, which is a first-order susceptible zone and has a linear relationship with the density of wild manure. However, both of them show a declining trend year by year. 300m, although there are changes in the years, but no law