Consider a finite subgroup G of SL_n(C). It is well-known that such subgroups correspond to Dynkin graphs of type ADE when n = 2. This can be seen by considering the dual graph of the configuration of the exceptional curves of the resolution of C^2/G. On the other hand, McKay gave an alternative definition of the same correspondence by considering representations of G. These two correspondences were compared by Gonzales-Sprinberg and Verdier by studing the K-theory of the resolution. In this talk, we consider similar correspondences when n = 3.