Abstract: Rainfall spatial variability is one of the major factors affacting the spatial variation of runoff production in loess regions. Some characteristics of rainfall spatial variability including point-area reduction relationship,frequency and structure are analyzed by using rainfall intensity data of 5,15,30 and 60 minutes durations observed on small catchments with highy dense rain gauge stations and good observation conditions. The internal relationshop between interval intensity and event rainfall are also studied. The results will provide a basis for the modelling of runoff production on small loess catchments.