  Motivated by application to multiple M5 branes, we study some properties of
non-Abelian two-form gauge theories. We note that the fake curvature condition
which is commonly used in the literature would restrict the dynamics to be
either a free theory or a topological system. We then propose a modification of
transformation law which simplifies the gauge transformation of 3-form field
strength and enables us to write down a gauge invariant action. We then argue
that a generalization of Stueckelberg mechanism naturally gives mass to the
two-form gauge field. For the application to multiple M5-branes, it should be
identified with the KK modes.
