Face recognition is a biometric which uses computer software to determine the identity of the individual. Face recognition falls into the category of biometrics which is the "Automatic recognition of a person using distinguishing traits". The edge is made up of those pixels at which there is an abrupt change in the intensity. These pixels are known as the edge pixels and are connected to give an edge. In this this research work, first a method has been developed for automatic edge detection of an digital image. Here, we have developed a mamdani's fuzzy inference system in MATLAB using fuzzy logic toolbox. A smallest possible 2*2 window is used as a scanning mask. Mask slides over the whole image pixel by pixel, first horizontally in topmost horizontal line and then reaching at the end of the line, it increments to check the next vertical location and it continues till the whole image is scanned. The FIS built has four inputs, each input representing a pixel for 2*2 mask, and one output that represents pixel under consideration. The rule editor consists of sixteen fuzzy rules. The system built is represented by the trapezoidal membership function to model the behavior of pixels.