After comparing various interpolation methods and analysis of the prac tical requirements in meteorological services, an interpolation method is propos ed to meet the requirements of both more accurate and higher quality visualizat ion of meteorological elements choroplethic map. The method is based on the basic C ress man algorithm, and optimized by some key issues. The applications demonstrate th at it w orks well in the meteorological service system, and improves the acuracy and obj ectivity of precipitation choroplethic map.