Ecological Stoichiometry (ES) refers to pattern of proportions of elements in organisms and products of ecological interactions. The idea has its source in Liebig, Lotka and Redfield. However, ES had long been at a dormant stage until end of 1980s when ecologists rediscovered the usefulness in linking nature at individual level to dynamics at ecosystem level via ecological interactions. For example, in ES, consumer-prey interactions in terms of element X and Y can be simply expressed as:

[Xa, Yb]consumer + [Xc, Yd]prey

→ q[Xa, Yb]consumer + [X(a+c-qa) ,Y(b+d-qb)] residue

This ecological “reaction” raised a number of questions: Is proportion of X and Y in an organism fixed? What is evolutionary basis of this proportion? How do consumers cope with elemental mismatching in their prey? What is fate of these elements in the residue? These questions have rapidly increased ES studies, and are contributing to deepen our ecological understandings. Here, I briefly talk about history and potential importance of ES as an appetizer, to stimulate your assimilation of the ES studies presented in this symposium.