  We consider the mass concentration phenomenon for the $L^2$-critical
nonlinear Schr\"odinger equations of higher orders. We show that any solution
$u$ to $iu_{t} + (-\Delta)^{\frac\alpha 2} u =\pm |u|^\frac{2\alpha}{d}u$,
$u(0,\cdot)\in L^2$ for $\alpha >2$, which blows up in a finite time, satisfies
a mass concentration phenomenon near the blow-up time. We verify that as
$\alpha$ increases, the size of region capturing a mass concentration gets
wider due to the stronger dispersive effect.
