Changing a variable-length code into an equal-length code is required in the feature match process of a conventional algorithm based on the zero-crossing of the wavelet transform proposed by Boles.The factor for the variability of the code length is complex,so it is difficult to change the variable-length code into the equal-length code compulsively and to avoid the effect of feature matching on the final recognition rate.To solve the above problem,an iris recognition algorithm based on the zero-crossing position of wavelet transform and matching using a variable-length code is proposed.Firstly,The zero-crossing position of the wavelet transform at each level from the 4th to the 8th decompose level is calculated,and then shift-matching algorithm is used to directly calculate the distance of the variable-length code.That is to say that the distance between the two samples is calculated at each relative shift.Finally the minimal distance is chosen as the distance between the two sample.Experiments are done with iris database containing 800 images,and the experimental results show that the recognition rate obtained by this method reaches 97.70％,which is about 5.16％ higher than that of Boles' method.For the feature extracting time and the match time is only 0.2 s,the proposed method can satisfy the system requirements of real time applications.