The professionalization of students' (physisists-mathematicians' and philologists') memory was studied. The participants (304 students) were required to reproduce a series of 30 words that could be groupped and of 21 unconnected words. The mean volume of memory was the same for both groups, but physisists-mathematicians' memory was of choice nature. They groupped the words by their sense, and the philologists did that by their formal properties. The differences manifested themselves in retroactive interference, particularly in its connection to progress in studies.