Street lighting delays autumnal leaf coloring and the leaf fall of some kind of deciduous trees. This phenomenon was reported in 1990 for the first time. However there is little information about the lighting conditions, which causes this phenomenon. The aim of this research was to clarify the degree of the light, which causes abnormal leaf coloring and the leaf fall, and to acquire fundamental knowledge for better lighting design to make roadside trees' growth condition and streetscape well. The investigation was performed on roadside trees, Liquidambar styraciflua, from November 16 in 2002 to January 11 in 2003. It was found that lighting of more than 20lux influences autumnal leaf coloring and the leaf fall, and especially lighting of more than 200lux influences more greatly. Based on the results, recommendations for lighting in urban streetscape are discussed.
