Mean curvature flow (MCF) is the higher dimensional analogue of curve shortening flow in a plane. There are many results on MCF of convex hypersurfaces in Euclidean spaces and spheres. Comparatively MCF of higher codimensional submanifolds and non-convex hypersurfaces are less understood. In this talk, I will describe the behavior of MCF for a class of submanifolds, called isoparametric submanifolds, which either have high codimension or have complicated topological type. This is based on a joint work with Chuu-Lian Terng.