A facial expression recognition system includes a facial database, an image capture unit, an expression recognition data generation unit and an expression recognition unit. The facial database includes a plurality of expression information and expression features of optical flow field, wherein each of the expression features of optical flow field corresponds to one of the expression information. The image capture unit captures a plurality of facial images. The expression recognition data generation unit is coupled to the image capture unit and the facial database for receiving a first facial image and a second facial image from the image capture unit and calculating an expression feature of optical flow field between the first facial image and the second facial image corresponding to each of the expression information. The expression recognition unit is coupled to the expression recognition data generation unit for determining a facial expression corresponding to the first and second facial images according to the calculated expression feature of optical flow field for each of the expression information and the variation features in optical flow in the facial database.
