The paper presents a method of automated license plate location, the first key step of the license plate recognition is to find and separate the license plate area from the image of license plate. In this article, the quality of the license plate image is improved though a series of digital image processing in the image pretreatment, and the quick and exact license plate location is realized based on the gray projection algorithm. Large numerous of plate license images are acquired and tested by the development platform of VC++6.0, and the result shows that the technology adopted in the article has good adaptability, especially it can quickly and reliably locate the license plate images shot under complex backgrounds.