The concept of agency has been frequently discussed in recent years. In this article,I examine Actor Network Theory and the concept of hybrid collective, both of which propose agency as a hybrid of human and non-human actors. In this theory, human actors and non-human actors are completely symmetrical and equivalent in their analytical procedure. While this symmetry is instructive in emphasizing the importance of non-human agency, it is also problematic in understanding the actualities of agency. To appreciate the concept of agency more precisely, it should be considered as a recursive,dynamic and historical achievement. Agency is an important concept; its theoretical distinctiveness will have an active influence upon the field of psychology and cognitive science.