Abstract: We present a BP neural network based classification method for iris image quality in view of such badquality image issues as insufficient light condition, glasses reflection and eyelid shelter in the process of iris image acquisition.We initially employ twodimensional wavelet transform to extract the features of an iris image, and then train a BP neural network with the extracted and normalized image as its input，finally.We therefore implement the goal of distinguishing the iris images affected by three different factors from unaffected images.Experimental results show that the method has higher classification accuracy and lower error rate.

Key words: quality classification, wavelet coefficient, iris image, BP neural network, wavelet transform