Based on the grey theory, the principle and processes of grey undee forecast were introduced.Combined with the fact of Shangcheng County, the annual rainfall undee forecast model was built.

• 摘要以灰色理论为基础，介绍了灰色波形预测的原理和步骤，并结合实际，建立了商城县年降雨量波形预测模型，对所建模型进行误差检验，结果表明该预测模型具有较好的可行性和较高的精度。