Until now, iris recognition has been used in many fields. Recently, there have been attempts to adopt iris recognition technology for the security of mobile phones. For example, in case of bank transaction service by using a mobile phone, using a mobile phone can use high level of security based on iris recognition. In this paper, we propose a new pupil & iris segmentation method apt for the mobile environment. We find the pupil & iris at the same time, using both information of the pupil and iris. And we also use characteristic of the eye image. Experimental result shows that our algorithm has good performance in various images, which include motion or optical blurring, ghost, specular refection and etc. from various environments for iris recognition system.