A novel iris recognition method is described based on the structures of irises. Firstly, we get the fixed-size iris image through the image preprocessing. Secondly, we detect all of the feature points in the iris image utilizing the method of finding local minimum points. Thirdly,we abandon the fake feature points and create the iris codes. Finally,we calculate the Hamming distance between two iris codes and obtain the recognition result according to the Hamming distance. The experimental results on 756 iris images show that the accuracy of the proposed method is higher than other recognition algorithms found in the current literatures, and the recognition speed is very fast.