Against the backdrop of the rapid and global advancement of iSchool movement,and based on an extensive reading of iSchool related literature,this paper reflects on the conceptualizations of LIS (Library and Information Science),iField and their relationships by iSchool proponents from the perspectives of disciplinary history,rationality and legitimacy. This exercise is conducted to inform future development of the iSchool movement in general and the participation of Chinese LIS sector in particular. The study shows that,essentially aimed at LIS education reformation,the iSchool movement has instigated nevertheless a disciplinary restructuring as well,with LIS being the primary target to transform and iField the target to achieve. To legitimize both iSchool movement and iField,LIS is conceptualized as an institution-based discipline serving primarily the library sector; by contrast,iField is conceptualized as an interdisciplinary field focusing on the interactions between people,information and technology. Little is explicitly mentioned about the relationship between iField and LIS,however,the objective of iSchools to rebuild their education programs based on a new discipline mandates implicitly the substitution of iField for LIS,which in turn,mandates the decomposition of LIS so that iField can take everything related to information (the I content of the previous LIS) into its core and shove everything related to the static library (the L content as perceived by iSchool proponents) to the periphery. From what the iSchool movement has unfolded so far,this appears indeed the fate awaiting LIS. Seen from the perspective of disciplinary history,the above conceptions have not only distorted LIS as a discipline,but also disconnected iField from LIS legacies that might help to define it. Having jettisoned these legacies,iSchools resort to three discrete elements-people,information and technologies-to define iField. However,this way of defining iField has made it almost impossible to logically delineate its boundary,which exposes the field to a problem of rationality if not a problem of legitimacy. This paper warned the LIS-turned iSchools that the historical trajectory of sciences indicates that we may be witnessing a new wave of disciplinary specializations surrounding information and information technologies,and that identifying themselves with a vague,all-encompassing and logically flawed discipline may risk losing the opportunity to demonstrate their uniqueness and unsubstitutability in comparison with other information related communities. This paper suggests that iSchools revisit the crisis of LIS education while distinguishing between LIS as a discipline and LIS as a community. This way,they may find that it is the community to blame after all. If this is the case,a new iField in lieu of LIS is arguably void of legitimacy. 3 figs. 65 refs.