Mitochondia are double membrane-bound organelles which are the main sites of energy production and cellular metabolism. The conserved MICOS complex acts as a primary determinant of mitochondrial crista structure. The bimolecular fluorescence complementation (BiFC) was used to study the interaction of MICOS subunits in live cells. We found that the Mic60 can interact with Mic19 directly, but the interaction was weak. Our data are important for illuminating the relationships of mitochondrial MICOS complex subunits.