Unusual precipitation refers to any precipitating subject but commomly observed raindrops, snowflakes, and hails. They include dust, sand, feather, silk, rice, grass, charcal, fish, meat, bone, worm, gold, coin, bloody-rain, bloody-snow and etc. A research project on "Reconstruction of Climate Data from Ancient Chinese History" was proposed by this study group and is funded by the National Science Council. Excerpts of unusual precipitation records from an edited computer file are the bases for analysis and discussion in this article. Causes of most of these precipitating subjects may be interpreted through meteorological consequences; such as typhoon, tornado, and dust-storm. While some of the peculiar events; such as sky-falling meat, coin, gold and etc. still remain unknown and reserved for further investigation.