The ATLAS detector at CERN's LHC will be exposed to proton-proton collisions at a nominal rate of 1 GHz from beams crossing at 40 MHz. A three-level trigger system will select potentially interesting events in order to reduce this rate to about 200 Hz. The first trigger level is implemented in custom-built electronics and firmware, whereas the higher trigger levels are based on software. A system for the configuration of the complete trigger chain is being constructed. It is designed to deliver all relevant configuration information - e.g. physics selection criteria like transverse momentum thresholds encoded in settings for level-1 hardware registers, parameter values of high-level trigger selection algorithms, algorithm versions used or prescale factors. The system should be easy to operate. It must store the history of each trigger setup for later analysis. The same system will be used to configure the offline trigger simulation. In this presentation an overview of the ATLAS trigger configuration system is given including the underlying relational database, and the tools for populating and accessing configuration information.