Automatic License Plate Detection and Recognition (ALPDR) system is an image processing technology used to identify cars by their license plates.This system consists of two main parts: the first is a practical implementation of how to take an automatically snapshotfor cars passes, this was done by two sensors type(GP2Y0A21YK0F sensor) connected with each other and interfaced with a A4tech USB camera,and this camera is interfaced using Matlab 2013a with the personal computer. The second part is image processing, this part includes four basic stages: The first stage is image preprocessing which involves image normalization and RGB to gray image conversion. Second stage is detection of a possible license plate using edge detection technique and extracts these LP using region growing technique, detection rates reach to 95%. Third stage is alphanumeric character segmentation to isolate each character, numbers and words of the license plate using Otsu's and Hough transforms technique for subsequent recognition. The last stage reads the alphanumeric character and words by correlation template matching, which is a simple, fast and given a recognition rate reach to 98.245%.