This volume is a collection of papers presented at the Sixth International Sympo- sium "Ultrafast Phenomena in Spectroscopy" (UPS '89) held in Neubrandenburg, GDR, August 23-26, 1989. This symposium brought together about 220 scien- tists from 18 European countries and from overseas. The participants are active in a wide range of scientific disciplines, including physics, chemistry, biology, opto-electronics and scientific instrumentation. They share a common interest in discussing problems and perspectives of ultrafast processes at picosecond and femtosecond time scales. UPS '89 was held...