Perennial ryegrass (Lolium perenne L.) is one of the most important grass species in the world's temperate zones. It is used as high-quality forage in pastures and for recreational use as turf in golf courses, lawns and parks. Genetic improvement of perennial ryegrass is difficult due to its self-incompatibility. Consequently, progress by conventional breeding can be slow. Genetic transformation is an alternative that permits direct introduction of useful genes into a plant's genome and is becoming a powerful tool to complement conventional breeding. To improve environmental stress tolerance and quality of perennial ryegrass by introducing better and useful genes into the genome, we have developed a rapid and efficient transformation system using Agrobacterium-mediated gene transfer system.