We discuss the relation between the elliptic genus of K3 surface and the Mathieu group M 24. We find that some of the twisted elliptic genera for K3 surface, defined for conjugacy classes of the Mathieu group M 24, can be represented in a very simple manner in terms of the η product of the corresponding conjugacy classes. It is shown that our formula is a consequence of the identity between the Borcherds product and additive lift of some Siegel modular forms.
!!!All Science Journal Classification (ASJC) codes