Abstract: Relating the iris recognition to the working mechanism of human brain, a method of restructuring the characteristic vector field is recommended. It calculates the lst-order differences separately from the rows of one normalized iris image and columns of another one, then the two differences are mapped to form a vector field. Based on the restructuring idea, the lst-order differences are further calculated from the rows of an iris image and from the columns of another iris image for restructuring a new characteristic vector field. Then, whether the two iris images are resulting from the same iris is judged by computing the restructuring distance between the two fields. Comparing the method with some other existing ones, it shows the advantage that its preprocessing procedure does not require denoising and image enhancing but reduces the time for computation. Moreover, because there is no filter in integral form used during computation, the method is adaptable to hardware implementation. With the match test done 285, 290 times, it was revealed that the rate of correct recognition is up to 98.81% by use of this method, thus verifying its validity.