The purpose of this study was to examine their identity transformation processes when undergraduate students were exploring tasks of career. I interviewed with students for three occasions in the period. As a framework for the analyses, I applied Grotevant's process model of identity formation for the data of this study. As a result, 11 of 22 cases were consistent with the prediction from the model. However, the other 11 cases could not be explained by the model. I classified these cases into the following five patterns: 1) The subjects did not voluntarily explore their tasks at all; 2) They did not explore their identity, although they explored the task of career; 3) They did both identity exploration and task exploration. However, those two processes were not well integrated into their identity; 4) They explored the task based only on their present identity without revising it; 5) They changed their identity through task exploration other than career planning. These results were discussed based on the way that they processed the task.