Abstract" distributed web-based system for temporal and spatial power quality analysis has been realized and tested. Connecting by internet local instruments able to perform high accuracy measurements in real time, the Power Quality information, locally measured, can be sent to a remote central server which aim is to plot them and stored the data for future analysis. The remote instruments have been realized, tested and placed in two Italian cities, Palermo and Rome, where actually work while the server works in Rome. The web application allows to select the single instrument and to show its stored PQ information.