The nutrient potassium of water-soaking solution for two kinds of coatedcompound fertilizer was determined by atomic absorption spectrophotometry, in which the recovery rate was 107.89 % for 6 samples and the correct, sensitive and quick potassium is provided for the formula design and release feature research of coated compound fertilizer 摘要用火焰原子吸收法,对两种复合肥料及其包膜肥料水溶出液中的养分钾进行了测定,测试中的6个样品平均加样回收率为107.89%,为包膜复合肥料配方设计和释放特性研究提供了准确、灵敏、快速的定钾方法。